Your Eye Health Explained

Glaucoma is a condition which can affect sight, usually due to build up of pressure within the eye.
Glaucoma often affects both eyes, usually to varying degrees. One eye may develop glaucoma quicker than the other.
The eyeball contains a fluid called aqueous humour which is constantly produced by the eye, with any excess drained though tubes.
Glaucoma develops when the fluid cannot drain properly and pressure builds up, known as the intraocular pressure.
This can damage the optic nerve (which connects the eye to the brain) and the nerve fibres from the retina (the light-sensitive nerve tissue that lines the back of the eye).

Types of glaucoma
There are four main types of glaucoma:

  • chronic open-angle glaucoma – this is the most common type of glaucoma and develops very slowly
  • primary angle-closure glaucoma – this is rare and can occur slowly (chronic) or may develop rapidly (acute) with a sudden, painful build-up of pressure in the eye
  • secondary glaucoma – this mainly occurs as a result of an eye injury or another eye condition, such as uveitis (inflammation of the middle layer of the eye)
  • developmental glaucoma (congenital glaucoma) – a rare but sometimes serious type of glaucoma which occurs in very young children, caused by an abnormality of the eye

Treating glaucoma
Glaucoma can be treated with eye drops, laser treatment or surgery. But early diagnosis is important because any damage to the eyes cannot be reversed. Treatment aims to control the condition and minimise future damage.
If left untreated, glaucoma can cause visual impairment. But if it’s diagnosed and treated early enough, further damage to vision can be prevented.

Preventing glaucoma
Attending regular optician appointments will help to ensure any signs of glaucoma can be detected early and allow treatment to begin.

You are entitled to a free NHS eye test if you are over 40 years old and have a first-degree relative (mother, father, sister or brother) with glaucoma.
You may also be entitled to a free NHS eye test if:

  • an ophthalmologist (eye specialist) thinks you are at risk of developing glaucoma
  • you are over 60 years old

How common is glaucoma?
In England and Wales, it’s estimated more than 500,000 people have glaucoma but many more people may not know they have the condition.
Chronic open-angle glaucoma affects up to two in every 100 people over 40 years old and around five in every 100 people over 80 years old.
You are also at increased risk of developing open-angle glaucoma if you are of black-African or black-Caribbean origin.
Some types of glaucoma, such as acute angle-closure glaucoma, are much less common. However, people of Asian origin are more at risk of getting this type of glaucoma compared with those from other ethnic groups.

Cataracts occur when changes in the lens of the eye cause it to become less transparent (clear). This results in cloudy or misty vision.
The lens is the crystalline structure that sits just behind your pupil (the black circle in the centre of your eye).
When light enters your eye, it passes through the cornea (the transparent layer of tissue at the front of the eye) and the lens, which focuses it on the light-sensitive layer of cells at the back of your eye (the retina).
Cataracts sometimes start to develop in a person’s lens as they get older, stopping some of the light from reaching the back of the eye.
Over time, cataracts become worse and start to affect vision. Eventually, surgery will be needed to remove and replace the affected lens.

Symptoms of cataracts
As cataracts develop over many years, problems may be unnoticeable at first. Cataracts often develop in both eyes, although each eye may be affected differently.
You’ll usually have blurred, cloudy or misty vision, or you may have small spots or patches where your vision is less clear.
Cataracts may also affect your sight in the following ways:

  • you may find it more difficult to see in dim or very bright light
  • the glare from bright lights may be dazzling or uncomfortable to look at
  • colours may look faded or less clear
  • everything may have a yellow or brown tinge
  • you may have double vision
  • you may see a halo (a circle of light) around bright lights, such as car headlights or street lights
  • if you wear glasses, you may find that they become less effective over time

Cataracts aren’t painful and don’t irritate your eyes or make them red.

When to see an optician
If you have problems with your vision, make an appointment to see your optician (also known as an optometrist). They can examine your eyes and test your sight.
The optician may look at your eyes with a slit lamp or ophthalmoscope. These instruments magnify your eye and have a bright light at one end that allows the optician to look inside and check for cataracts.
If your optician thinks you have cataracts, they may refer you to an ophthalmologist or an ophthalmic surgeon, who can confirm the diagnosis and plan your treatment. These doctors specialise in eye conditions, such as cataracts, and their treatment.

Who’s affected
Cataracts are very common and they’re the main cause of impaired vision worldwide.
In the UK, most people who are aged 65 or older have some degree of visual impairment caused by cataracts. Men and women are equally affected.
Even though cataracts tend to affect older people (known as age-related cataracts), they can also sometimes affect babies and young children
What causes age-related cataracts?
The reasons why age-related cataracts develop aren’t fully understood. Like grey hair, cataracts are an inevitable part of ageing that affect different people at different ages.
Cataracts are the result of changes in the structure of the lens over time. It’s thought that the cloudy areas in the lens may be caused by changes in the proteins that make up the lens. However, it’s not clear how or why getting older cause these changes to occur.
As well as your age, there are a number of other factors that may increase your risk of developing cataracts. These include:

  • having a family history of cataracts
  • having diabetes
  • having other eye conditions, such as long-term uveitis
  • eye surgery or an eye injury
  • taking a high dose of corticosteroid medication, or taking corticosteroids for a prolonged period of time

Other factors that may possibly be linked to the development of cataracts include:

  • smoking
  • regularly drinking excessive amounts of alcohol
  • a poor diet lacking in vitamins
  • lifelong exposure to sunlight

As the exact cause of age-related cataracts isn’t clear, there’s no known way to prevent them.

Treating age-related cataracts
If your cataracts aren’t too bad, stronger glasses and brighter reading lights may help. However, as cataracts get worse over time, it’s likely that you’ll eventually need treatment.
Surgery is the only type of treatment that’s proven to be effective for cataracts. It’s usually recommended if loss of vision has a significant effect on your daily activities, such as driving or reading.
Cataract surgery involves removing the cloudy lens through a small incision in your eye and replacing it with a clear, plastic one. In most cases, the procedure is carried out under local anaesthetic (where you’re conscious, but the eye is numbed) and you can usually go home the same day.
Almost everyone who has cataract surgery experiences an improvement in their vision, although it can sometimes take a few days or weeks for your vision to settle. You should be able to return to most of your normal activities within about two weeks.
After the operation, your plastic lens will be set up for a certain level of vision, so you may need to wear glasses to see objects that are either far away or close by. If you wore glasses previously, your prescription will probably change. However, your optician will need to wait until your vision has settled before they can give you a new prescription.

Age-related macular degeneration (AMD) is a painless eye condition that causes you to lose central vision, usually in both eyes.
Central vision is what you see when you focus straight ahead. In AMD, this vision becomes increasingly blurred, which means:

  • reading becomes difficult
  • colours appear less vibrant
  • people’s faces are difficult to recognise

This sight loss usually happens gradually over time, although it can sometimes be rapid.
AMD doesn’t affect your peripheral vision (side vision), which means it will not cause complete blindness.

When to seek medical advice
Visit your GP or optometrist if your vision is getting gradually worse. If your vision suddenly gets worse, images are distorted or you notice blind spots in your field of vision, seek medical advice immediately and book an emergency appointment with an optometrist.
If AMD is suspected, you’ll be referred to an ophthalmologist (eye specialist) for tests and any necessary treatment.

Why it happens
Macular degeneration develops when the part of the eye responsible for central vision (the macula) is unable to function as effectively as it used to. There are two main types – dry AMD and wet AMD.

Dry AMD develops when the cells of the macula become damaged by a build-up of deposits called drusen. It’s the most common and least serious type of AMD, accounting for around 9 out of 10 cases.
Vision loss is gradual, occurring over many years. However, an estimated 1 in 10 people with dry AMD go on to develop wet AMD.

Wet AMD – sometimes called neovascular AMD – develops when abnormal blood vessels form underneath the macula and damage its cells.
Wet AMD is more serious than dry AMD. Without treatment, vision can deteriorate within days.

Who’s affected?
AMD currently affects more than 600,000 people in the UK and is the leading cause of vision loss. By 2020, it’s predicted almost 700,000 people will have late-stage AMD in the UK.
For reasons that are unclear, AMD tends to be more common in women than men. It’s also more common in white and Chinese people.
The condition is most common in people over the age of 50. It’s estimated 1 in every 10 people over 65 have some degree of AMD.

Treating macular degeneration
There’s currently no cure for either type of AMD. With dry AMD, treatment aims to help a person make the most of their remaining vision – for example, magnifying lenses can be used to make reading easier.
There’s some evidence to suggest a diet rich in leafy green vegetables may slow the progression of dry AMD.
Wet AMD can be treated with anti-vascular endothelial growth factor (anti-VEGF) medication. This aims to stop your vision getting worse by preventing further blood vessels developing.
In some cases, laser surgery can also be used to destroy abnormal blood vessels.
The early diagnosis and treatment of wet AMD is essential for reducing the risk of severe vision loss.

Reducing your risk
It’s not always possible to prevent macular degeneration because it’s not clear exactly what triggers the processes that cause the condition.
Your risk of developing AMD is closely linked to your age and whether you have a family history of the condition.
However, you may be able to reduce your risk of developing AMD, or help prevent it getting worse, by:

  • stopping smoking if you smoke
  • eating a healthy, balanced diet that includes plenty of fruit and vegetables
  • moderating your consumption of alcohol – read more about alcohol units and recommendations
  • trying to achieve or maintain a healthy weight
  • wearing UV-absorbing glasses when outside for long periods

Blepharitis is a common condition where the edges of the eyelids (eyelid margins) become red and swollen (inflamed).
Blepharitis can develop at any age, and symptoms can include:

  • itchy, sore and red eyelids that stick together
  • crusty or greasy eyelashes
  • a burning, gritty sensation in your eyes
  • increased sensitivity to light (photophobia)
  • swollen eyelid margins
  • finding contact lenses uncomfortable to wear
  • abnormal eyelash growth or loss of eyelashes in severe cases

In most cases both eyes are affected, but one eye can be more affected than the other. The symptoms tend to be worse in the morning.
When to get medical advice
See your high-street optician (optometrist) if you have persistent symptoms of blepharitis that aren’t being controlled by simple eyelid hygiene measures.
They can examine you to check if the problem is caused by an underlying condition, or may refer you to an eye specialist.
Contact your optometrist or GP immediately if you have any severe symptoms. If this isn’t possible, visit your nearest A&E

How blepharitis is treated
Blepharitis is usually a long-term condition. Most people experience repeated episodes, separated by periods without symptoms.
It can’t usually be cured, but a daily eyelid-cleaning routine can help control the symptoms and prevent permanent scarring of the eyelid margins.
There are three main steps to eyelid hygiene that should be performed once or twice a day:

  • using a warm compress – to make the oil produced by the glands around your eyes more runny
  • gently massaging your eyelids – to push the oils out of the glands
  • cleaning your eyelids – to wipe away any excess oil and remove any crusts, bacteria, dust or grime that might have built up

More severe cases may require antibiotics that are either applied to the eye or eyelid directly, or taken as tablets.

What causes blepharitis?
There are three main types of blepharitis:

  • anterior blepharitis – where the inflammation affects the skin around the base of your eyelashes
  • posterior blepharitis – where the inflammation affects your Meibomian glands, found along the eyelid margins behind the base of the eyelashes
  • mixed blepharitis – a combination of both anterior and posterior blepharitis

Anterior blepharitis can be caused by either:

  • a reaction to Staphylococcus bacteria – these usually live harmlessly on the skin of many people, but for unknown reasons they can cause the eyelids to become inflamed
  • seborrhoeic dermatitis – a skin condition that causes skin to become oily or flaky and sometimes irritate the eyelids, causing the Meibomian glands to block

Posterior blepharitis is caused by a problem with the Meibomian glands, where the glands get blocked by either debris, skin flakes or inflammation.
Sometimes blockages in the Meibomian glands are associated with a skin condition called rosacea. If too much oily substance is being produced, this may be caused by seborrhoeic dermatitis.
Mixed blepharitis, which is the most common, is caused by a combination of both anterior and posterior blepharitis.
Blepharitis isn’t contagious.

Blepharitis isn’t usually serious, although it can lead to a number of further problems.
For example, many people with blepharitis also develop dry eye syndrome, where the eyes don’t produce enough tears or dry out too quickly. This can cause your eyes to feel dry, gritty and sore.
Serious, sight-threatening problems are rare, particularly if any complications that develop are identified and treated quickly.

Conjunctivitis is a common condition that causes redness and inflammation of the thin layer of tissue that covers the front of the eye (the conjunctiva).
People often refer to conjunctivitis as Red Eye

Other symptoms of conjunctivitis include itchiness and watering of the eyes, and sometimes a sticky coating on the eyelashes (if it’s caused by an allergy).

Conjunctivitis can affect one eye at first, but usually affects both eyes after a few hours.
What causes conjunctivitis?
The conjunctiva can become inflamed as a result of:

  • a bacterial or viral infection – this is known as infective conjunctivitis
  • an allergic reaction to a substance such as pollen or dust mites – this is known as allergic conjunctivitis
  • the eye coming into contact with things that can irritate the conjunctiva, such as shampoo or chlorinated water, or a loose eyelash rubbing against the eye – this is known as irritant conjunctivitis

Treating conjunctivitis
Treatment isn’t usually needed for conjunctivitis because the symptoms often clear up within a couple of weeks. If treatment is needed, the type of treatment will depend on the cause. In severe cases, antibiotic eye drops can be used to clear the infection.
Irritant conjunctivitis will clear up as soon as whatever is causing it is removed.
Allergic conjunctivitis can usually be treated with anti-allergy medications such as antihistamines. If possible, you should avoid the substance that triggered the allergy.
It’s best not to wear contact lenses until the symptoms have cleared up. Any sticky or crusty coating on the eyelids or lashes can be cleansed with cotton wool and water.
Washing your hands regularly and not sharing pillows or towels will help prevent it spreading.

See your GP immediately if you have:

  • eye pain
  • sensitivity to light (photophobia)
  • disturbed vision
  • intense redness in one eye or both eyes
  • a newborn baby with conjunctivitis

Conjunctivitis can be a frustrating condition – particularly allergic conjunctivitis – but in most cases it doesn’t pose a serious threat to health.
Complications of conjunctivitis are rare, but when they do occur they can be serious and include:

  • a severe case of allergic conjunctivitis can lead to scarring in the eye
  • in cases of infective conjunctivitis, the infection can spread to other areas of the body, triggering more serious secondary infections, such as meningitis

Dry eye syndrome can occur if your eyes don’t produce enough tears or your tears evaporate too quickly.
This may happen if any part of the tear production process becomes disrupted and the quantity or quality of your tears is affected.
There are many different reasons why this can happen, although a single identifiable cause may not be found. Some of the possible causes are described below.
Hormonal changes
Hormones – powerful chemicals produced by the body and the nervous system – play an important part in tear production.
Hormones stimulate the production of tears. Changes in hormone levels in women can increase their risk of dry eye syndrome. For example:

  • during pregnancy
  • during the menopause
  • while using the contraceptive pill

Dry eye syndrome is more common in older people. This may be because you produce fewer tears as you get older, and your eyelids become less effective at spreading tears over the surface of the eyes.
Environment and activities
Environmental factors can have a drying effect on your eyes, causing your tears to evaporate. These include:

  • sun
  • wind
  • dry climate
  • hot blowing air
  • high altitude

Certain activities can also contribute to dry eye syndrome, such as:

  • reading
  • writing
  • working with a computer

People tend to blink less frequently during activities that require visual concentration. This means the tear film evaporates or drains away more quickly than it’s replenished.

Certain medications
Several medicines are thought to cause dry eye syndrome as a side effect in some people, including:

  • antihistamines
  • antidepressants
  • beta-blockers
  • diuretics

Laser eye surgery
Some people who have had certain types of laser eye surgery find they have dry eye syndrome in the weeks after surgery.
The symptoms usually clear up after a few months, but in some cases may continue.

Contact lenses
Sometimes contact lenses irritate the eye and cause dry eye syndrome. Changing to a different type of lens or limiting how often you use your contact lenses usually helps resolve the symptoms, or you can try changing cleaning solutions or using preservative-free lubricant eye drops.

Medical conditions
There are a number of medical conditions that increase your risk of developing dry eye syndrome.
Many people with dry eye syndrome also have blepharitis or meibomian gland dysfunction (MGD). This is where the eyelid margins become inflamed, which can block the glands that produce oils for the tear film.
Blepharitis can occur at any age and in otherwise healthy people although it sometimes occurs as the result of a bacterial infection or other conditions, such as rosacea, a skin condition that causes the face to appear red and blotchy.
Other medical conditions that can increase your risk of dry eye syndrome include:

  • allergic conjunctivitis – inflammation of the transparent layer of cells that covers the white part of the eyeball and the inner surfaces of the eyelids (conjunctiva) caused by an allergy, usually to pollen and dust mites
  • contact dermatitis – a type of eczema that causes inflammation of the skin when you come into contact with a particular substance you’re sensitive to
  • Sjögren’s syndrome – a condition that can cause excessive dryness of the eyes, mouth and vagina, which is also associated with fatigue and arthritis
  • rheumatoid arthritis – a condition that causes pain, swelling and inflammation in the joints that can affect any part of the body, including the glands around the eyes and inflammation of the white of the eye (scleritis)
  • lupus – a condition where the immune system attacks healthy body tissue, particularly blood vessels
  • scleroderma – a condition where the immune system causes inflammation of the blood vessels and areas of skin to become hard and thickened
  • previous trauma (serious injury) to the eyes – such as burns or exposure to radiation
  • Bell’s palsy – a condition that causes weakness or paralysis to the muscles of one side of the face

Diabetic retinopathy is a complication of diabetes, caused by high blood sugar levels damaging the back of the eye (retina). It can cause blindness if left undiagnosed and untreated.
However, it usually takes several years for diabetic retinopathy to reach a stage where it could threaten your sight.
To minimise the risk of this happening, people with diabetes should:

  • ensure they control their blood sugar levels, blood pressure and cholesterol
  • attend diabetic eye screening appointments – annual screening is offered to all people with diabetes aged 12 and over to pick up and treat any problems early on

How diabetes can affect the eyes
The retina is the light-sensitive layer of cells at the back of the eye that converts light into electrical signals. The signals are sent to the brain and the brain turns them into the images you see.
The retina needs a constant supply of blood, which it receives through a network of tiny blood vessels. Over time, a persistently high blood sugar level can damage these blood vessels in three main stages:

  • tiny bulges develop in the blood vessels, which may bleed slightly but don’t usually affect your vision – this is known as background retinopathy
  • more severe and widespread changes affect the blood vessels, including more significant bleeding into the eye – this is known as pre-proliferative retinopathy
  • scar tissue and new blood vessels, which are weak and bleed easily, develop on the retina – this is known as proliferative retinopathy and it can result in some loss of vision

However, if a problem with your eyes is picked up early, lifestyle changes and/or treatment can stop it getting worse.

Am I at risk of diabetic retinopathy?
Anyone with Type 1 of Type 2 diabetes is potentially at risk of developing diabetic retinopathy.
You’re at a greater risk if you:

  • have had diabetes for a long time
  • have a persistently high blood sugar (blood glucose) level
  • have high blood pressure
  • have high cholesterol
  • are pregnant
  • are of Asian or Afro-Caribbean background

By keeping your blood sugar, blood pressure and cholesterol levels under control, you can reduce your chances of developing diabetic retinopathy.

Symptoms of diabetic retinopathy
You won’t usually notice diabetic retinopathy in the early stages, as it doesn’t tend to have any obvious symptoms until it’s more advanced.
However, early signs of the condition can be picked up by taking photographs of the eyes during diabetic eye screening.

Contact your GP or diabetes care team immediately if you experience:

  • gradually worsening vision
  • sudden vision loss
  • shapes floating in your field of vision
  • blurred or patchy vision
  • eye pain or redness

These symptoms don’t necessarily mean you have diabetic retinopathy, but it’s important to get them checked out. Don’t wait until your next screening appointment.

Diabetic eye screening
Everyone with diabetes who is 12 years old or over is invited for eye screening once a year.
Screening is offered because:

  • diabetic retinopathy doesn’t tend to cause any symptoms in the early stages
  • the condition can cause permanent blindness if not diagnosed and treated promptly
  • screening can detect problems in your eyes before they start to affect your vision
  • if problems are caught early, treatment can help prevent or reduce vision loss

The screening test involves examining the back of the eyes and taking photographs. Depending on your result, you may be advised to return for another appointment a year later, attend more regular appointments, or discuss treatment options with a specialist.

Reduce your risk of diabetic retinopathy
You can reduce your risk of developing diabetic retinopathy, or help prevent it getting worse, by:

  • controlling your blood sugar, blood pressure and cholesterol levels
  • taking your diabetes medication as prescribed
  • attending all your screening appointments
  • getting medical advice quickly if you notice any changes to your vision
  • maintaining a healthy weight, eating a healthy, balanced diet, exercising regularly and stopping smoking

Treatments for diabetic retinopathy
Treatment for diabetic retinopathy is only necessary if screening detects significant problems that mean your vision is at risk.
If the condition hasn’t reached this stage, the above advice on managing your diabetes is recommended.
The main treatments for more advanced diabetic retinopathy are:

  • laser treatment
  • injections of medication into your eyes
  • an operation to remove blood or scar tissue from your eyes

Floaters are small shapes that some people see floating in their field of vision.
They can be different shapes and sizes and may look like:

  • tiny black dots
  • small, shadowy dots
  • larger cloud-like spots
  • long, narrow strands

You may have many small floaters in your field of vision or just one or two larger ones. Most floaters are small and quickly move out of your field of vision.
Floaters are often most noticeable when you’re looking at a light-coloured background, such as a white wall or clear sky.

Do floaters affect vision?
Floaters sometimes occur without a person noticing them. This is because the brain constantly adapts to changes in vision and learns to ignore floaters so they don’t affect vision.
Floaters are usually harmless and don’t significantly affect your vision. However, it’s important you have your eyes checked by an optician regularly (at least once every two years).
Larger floaters can be distracting and may make activities involving high levels of concentration, such as reading or driving, difficult.

What causes floaters?
Floaters are small pieces of debris that float in the eye’s vitreous humour. Vitreous humour is a clear, jelly-like substance that fills the space in the middle of the eyeball.
The debris casts shadows on to the retina (the light-sensitive tissue lining the back of the eye). If you have floaters, it’s these shadows you’ll see.
Floaters can occur as your eyes change with age. In most cases, they don’t cause significant problems and don’t require treatment.
In rare cases, floaters may be a sign of a retinal tear or retinal detachment (where the retina starts to pull away from the blood vessels that supply it with oxygen and nutrients).

Floaters can’t be prevented because they’re part of the natural ageing process.
When to seek medical help
Visit your optician immediately if you notice an increase or sudden change in your floaters, particularly if you notice white flashes and some loss of vision.
Your optician may refer you to an ophthalmologist (a specialist in diagnosing and treating eye conditions) who can check your retina for tears or retinal detachment.
Even though floaters are usually harmless and don’t significantly affect your vision, it’s important you have your eyes checked regularly by an optician (at least once every two years).

Treating floaters
In most cases, floaters don’t cause major problems and don’t require treatment. Eye drops or similar types of medication won’t make floaters disappear.
After a while, your brain learns to ignore floaters and you may not notice them.
If your floaters don’t improve over time, or if they significantly affect your vision, a vitrectomy may be recommended. This is a surgical operation to remove the vitreous humour in your eye along with any floating debris and replace it with a saline (salty) solution.
If your retina has become detached, surgery is the only way to re-attach it. Without surgery, a total loss of vision is almost certain. In 90% of cases, only one operation is needed to re-attach the retina.

Long-sightedness (hyperopia) is often corrected with prescription glasses or contact lenses. In some cases, laser surgery is also an effective treatment option.

Long-sightedness can usually be corrected with glasses made to your prescription. Convex lenses (thinner at the edge than at the centre) are used to correct long sight.
The curvature of the lens, its thickness and weight will depend on how severe your long-sightedness is. By wearing a lens made to your prescription, light rays will fall onto your retina, allowing you to focus accurately.
The lens of the eye becomes stiffer with age, so the strength of your prescription may need to be increased as you get older.
It is possible to be both long- and short-sighted. If this is the case, you may need to wear two different pairs of glasses. Alternatively, you could wear varifocal or bifocal lenses, which allow you to clearly see objects that are both near and far.

Contact lenses
Contact lenses can also be used to correct long-sightedness in the same way as glasses. Some people prefer contact lenses to glasses because they are lightweight and virtually invisible.
Contact lenses are available in many different materials and designs. Some lenses can be worn for a day and discarded (daily disposables). Others can be disinfected and re-used, or worn for longer periods and kept in overnight. Your optometrist can advise about the most suitable lens for you.
If you wear contact lenses, it’s important that you maintain good lens hygiene to prevent eye infections developing.

Surgical treatments
There are various surgical techniques to treat long-sightedness. The most reliable uses laser surgery.
Surgical treatment for long-sightedness involves increasing the curvature of the cornea to improve its focusing power by removing some tissue from the edge of the cornea.
The benefit of laser surgery compared with traditional surgery is that instruments do not have to enter the eye, which means that the risk of damage or infection is lower.
There are three main types of laser surgery:
Laser in situ keratectomy (LASIK)
Laser in situ keratectomy (LASIK) is the most common procedure used for laser surgery in the UK.
A small instrument is used to cut a flap in the surface of the cornea, which is then folded back.
A laser is used to change the shape of the cornea, after which the flap is folded back down to its original position and held in place by natural suction.
Photorefractive keratectomy (PRK) 
Photorefractive keratectomy (PRK) is where a small amount of the surface of the cornea is removed, and a laser is used to remove tissue and change the shape of the cornea.
The removal of tissue is controlled by a computer, and the amount removed will depend on how poor your eyesight is. The surface of the cornea is then left to heal.
Laser epithelial keratomileusis (LASEK)
Laser epithelial keratomileusis (LASEK) is a similar procedure to PRK, but involves using alcohol to loosen the surface of the cornea before it is removed.
As with PRK, a laser is used to change the shape of the cornea. The surface of the cornea is then put back and held in place by natural suction.
The surgical procedure
Laser surgery is usually carried out on an outpatient basis. This means that you will not have to stay in hospital overnight, but will have one or more appointments at a clinic. The treatment usually takes between 30 and 60 minutes.
LASIK is usually the preferred treatment option, because it causes virtually no pain and your vision recovers quickly (within one or two days).
However, LASIK is a more complicated procedure, and if complications do occur, they may be more serious.
Although your vision will recover quickly after having LASIK, you may experience some fluctuations in vision, and it can take up to a month for your vision to stabilise completely.
LASIK treatment can only be carried out if your cornea is thick enough. If your cornea is too thin, the risk of complications and side effects, such as vision loss, is too great.
It may be possible for you to have LASEK or PRK if your cornea is not thick enough for LASIK surgery. The recovery time tends to be longer for these techniques – for example, it can take up to six months for your vision to fully stabilise after having PRK surgery.
The Royal College of Ophthalmologists provides more information about laser refractive surgery.
Who cannot have laser surgery?
You should not have any sort of laser surgery if you are under 21, because your vision is still changing and it is dangerous to alter the structures of your eyes at this stage.
If you are over 21, changes to your vision can still occur. Before having laser treatment, your clinic should check your glasses or contact lens prescriptions to confirm that your vision has not changed significantly over the last two years.
Laser surgery may also not be suitable if you:

  • have diabetes – which can cause abnormalities in the eyes that can be made worse by laser surgery
  • are pregnant or breastfeeding – your body will contain hormones that cause slight fluctuations in your eyesight and focusing power, making precise surgery too difficult
  • have a condition that affects your immune system – such as HIV or rheumatoid arthritis; this may affect your ability to recover after surgery
  • have other problems with your eyes – such as glaucoma (a condition that causes pressure changes in the eye and may lead to blindness) and cataracts (where the lenses harden and become cloudy)

Risks of laser surgery
As with all types of surgery, laser surgery carries some risks, and you should discuss these with your surgeon before deciding to have the procedure.
Some possible complications of laser surgery are:

  • Following surgery, your vision may be worse if the surgeon misjudges the amount of tissue taken from your cornea (this is known as a correction error).
  • The flap cut into your cornea may start to grow into the main part of your cornea when it is replaced (this is known as epithelial ingrowth, and it can cause vision problems that may require further surgery to correct).
  • Your cornea can become too thin, leading to a reduction in or loss of vision (this is called ectasia).
  • Your cornea can become infected (known as microbial keratitis).

It’s important to note, however, that the above risks are rare.

Treating age-related long-sightedness (presbyopia)
Laser surgery is not suitable for age-related long-sightedness (presbyopia), as it is caused by changes in the lens rather than the shape of the cornea.
Age-related long-sightedness is usually treated with glasses or contact lenses (see above).
Presbyopic lens exchange (PRELEX)
In some cases, surgery may be used to insert an artificial lens in the cornea. This is known as presbyopic lens exchange (PRELEX). PRELEX is usually offered to people who struggle to use glasses or contact lenses.
The procedure is normally performed using local anaesthetic (where you are awake, but the eye is numb) on the weaker eye. A small flap is made in the cornea, and an artificial lens is placed inside. The flap is then folded down and stays in place naturally, without stitches.
Corticosteroids and antibiotics are usually prescribed for a short period after surgery, and artificial tears may also be needed.
As PRELEX is a newer type of treatment, there is currently a lack of good evidence on its long-term safety, and the risks should be discussed with you before the procedure. The decision about whether this procedure can be performed on the NHS will be made by your local clinical commissioning group (CCG).

Short-sightedness, or myopia, is a very common eye condition that causes distant objects to appear blurred, while close objects can be seen clearly.
It’s thought to affect up to one in three people in the UK and is becoming more common.
Short-sightedness can range from mild, where treatment may not be required, to severe, where a person’s vision is significantly affected.
The condition usually starts around puberty and gets gradually worse until the eye is fully grown, but it can also develop in very young children.
Signs that your child may be short-sighted can include:

  • needing to sit near the front of the class at school because they find it difficult to read the whiteboard
  • sitting close to the TV
  • complaining of headaches or tired eyes
  • regularly rubbing their eyes

Getting your eyes tested
If you think you or your child may be short-sighted, you should book an eye test at a local opticians.

You should have a routine eye test at least every two years, but you can have a test at any point if you have any concerns about your vision.
An eye test can confirm whether you’re short or long-sighted, and you can be given a prescription for glasses or contact lenses to correct your vision.
For some people – such as children under 16, or those under 19 and in full-time education – eye tests are available free of charge on the NHS.

What causes short-sightedness?
Short-sightedness usually occurs when the eyes grow slightly too long.
This means that light doesn’t focus on the light-sensitive tissue (retina) at the back of the eye properly. Instead, the light rays focus just in front of the retina, resulting in distant objects appearing blurred.
It’s not clear exactly why this happens, but it often runs in families and has been linked to focusing on nearby objects, such as books and computers, for long periods during childhood.
Ensuring your child regularly spends time playing outside may help to reduce their risk of becoming short-sighted.

Treatments for short-sightedness
Short-sightedness can usually be corrected effectively with a number of treatments.
The main treatments are:

  • corrective lenses – such as glasses or contact lenses to help the eyes focus on distant objects
  • laser eye surgery to alter the shape of the eye – this isn’t usually available on the NHS and shouldn’t be carried out on children, whose eyes are still developing
  • artificial lens implants – where a man-made lens is permanently inserted into the eyes to help them focus correctly; these are also not usually available on the NHS

Associated eye conditions
Some adults with severe short-sightedness and young children with untreated short-sightedness are more likely to develop other eye problems.
These can include:

  • a squint – a common childhood condition where the eyes point in different directions
  • a lazy eye –  a childhood condition where the vision in one eye doesn’t develop properly
  • glaucoma – increased pressure inside the eyes
  • cataracts – where cloudy patches develop inside the lens of the eye

retinal detachment – where the retina pulls away from the blood vessels that supply it with oxygen and nutrients