Look after your eyes
Why regular eye tests are important and how a healthy lifestyle can help you maintain good vision
Symptoms of long-sightedness
If you are long-sighted (hyperopia), you can see distant objects clearly, but objects near to you are out of focus.
The eyesight of adults often deteriorates with age. Long-sightedness in adults (presbyopia) often becomes more noticeable after the age of 40.
If you develop long-sightedness, you may notice that:
nearby objects are fuzzy and out of focus, but distant objects are clear
you have to squint to see clearly
your eyes may feel tired after activities that involve focusing on nearby objects, such as reading, writing or working on a computer
you experience pain or burning in your eyes
you experience headaches
Children who are long-sighted do not often have problems with their eyesight. The lenses in children's eyes tend to be more flexible than those of adults and are able to compensate for long-sightedness.
However, it is still important that young children have regular eyesight tests to check for conditions such as long-sightedness.
If left untreated, long-sightedness can lead to complications such as crossed eyes (strabismus) or lazy eye (amblyopia).
If your child is severely long-sighted, the signs and symptoms may include:
Causes of long-sightedness
If a person suffers from long-sightedness (hyperopia), closeobjects appear blurred because the light that enters the eye is focused behind the retina, instead of on it.
This may occur if the:
As it is not possible for light to be focused behind the retina, the lens tries to correct this refractive error by changing its thickness, becoming fatter. This process is called accommodation.
If you are long-sighted, it is not possible to accommodate fully, which means light cannot be sharply focused, and vision will be blurred.
Long-sightedness can be caused by several factors, which are described below.
Long-sightedness can occur at any age, but it is often more noticeable after the age of 40.
Age-related long-sightedness is known as presbyopia. It develops when the lens in your eye becomes stiffer.
Long-sightedness is thought to be a condition that some people inherit from their parents.
However, with the exception of a rare form of hyperopia called nanophthalmos, specific genes for long-sightedness have yet to be identified, and further research is needed.
In rare cases, long-sightedness can be caused by other, underlying conditions, including:
microphthalmia (small eye syndrome), where a baby’s eyes do not develop properly during pregnancy
tumours around the eye (orbital tumours)
foveal hypoplasia, where there is a problem with the blood vessels in the retina
ow the eye works
The parts of the eye that help you to see are:
the cornea – the transparent layer at the front of the eye
the lens – the transparent crystalline structure that focuses light on to the retina
the retina – the light-sensitive layer that lines the interior of the back of the eye
the optic nerve – which transmits images from the retina to the brain
Light enters the eye through the cornea. The light rays pass through the lens and are focused onto the retina as an image. The retina converts the image into electrical signals, which are then transmitted to the brain by the optic nerve.
It's important for young children to have regular eye tests, so that any problems are detected early.
Most childhood eye conditions can be corrected. However, without treatment, they can lead to more serious problems that could affect your child's eyesight permanently.
Your child will have their eyesight checked several times as part of theroutine screening programme. You can also make an appointment for your child to have their eyes tested at any time, if you are concerned about their vision.
Eye tests are free for children under the age of 16 (under 19 for those in full-time education).
It's also important for adults to visit their optician regularly. The College of Optometrists recommends that you have your eyes tested at least every two years.
Regular check-ups will help identify conditions such as long-sightedness at an early stage, so that corrective treatment can be given.
Eye tests are carried out by an optometrist and usually take 20-30 minutes. During the test, your vision and the health of your eyes will be checked.
An eye test will usually include:
These are described below.
History and symptoms
The optometrist will start by asking whether you have any specific problems with your sight and how long it has been going on.
They may also ask about your general level of health, including any medication you take and your lifestyle.
An optometrist will check that your eyes are healthy and that you do not have any underlying medical problems.
They will examine the inside of your eye using an opthalmoscope, which is a torch that shines light through your pupil. This also tests your pupil reflexes (whether your pupils shrink in response to light).
Your eye movements and co-ordination will also be checked to make sure both of your eyes are working together.
Other tests may also be carried out, depending on your age and medical history. Eye conditions that your optician will be looking for include:
glaucoma – pressure changes in the eye that can damage the optic nerve
diabetic retinopathy – where high blood pressure and high blood sugar cause new blood vessels to form in the eye, which can obscure your vision
If you wear glasses or contact lenses, your vision will usually be tested both with and without them (so remember to take them with you).
The optometrist will usually assess your distance vision, your near vision (for reading and close work) and your intermediate vision (for using a computer).
A simple visual acuity test will help the optometrist assess how good your vision is. You may be asked to read from a Snellen chart, which is a series of letters that become progressively smaller on each line.
Your optometrist will then carry out further tests to determine the extent of your problem, and the exact type of corrective lenses that you need.
After your eye test
After your eye test, the optometrist will discuss your results with you and the best course of action. This will usually be a prescription for glasses or contact lenses to correct any sight problems you may have.
If your eyesight is okay, you will receive a statement to confirm that no correction is needed. If you need medical treatment, you may be referred to your GP or hospital.
Children with long-sightedness who have a squint need to be monitored carefully to avoid a lazy eye developing.
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 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.
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 will be made by your local clinical commissioning group (CCG).
Laser surgery to correct long-sightedness is not usually available.
It is generally only available free of charge for eye conditions, such asdiabetic retinopathy, when the treatment is essential to save someone's vision.
Complications of long-sightedness
Adults rarely have complications as a result of long-sightedness (hyperopia). In children, severe hyperopia can cause them to'over-focus', leading to double vision and two other eye conditions.
Long-sightedness in adults (presbyopia) is likely to get worse with age. However, a prescription for stronger glasses or contact lenses will enable most people to retain normal vision.
In children, severe long-sightedness can cause them to "over-focus" and experience double vision. This can lead to one eye turning away, resulting in a squint or lazy eye.
A squint (strabismus) is where the eyes are not properly aligned with each other, so they both focus on different things.
It can lead to problems judging how far away objects are from you (depth perception). It can also cause your brain to ignore the output of one eye, which can weaken the eye and lead to a lazy eye (see below).
Lazy eye (amblyopia)
Lazy eye (amblyopia) is where one eye becomes dominant over the other, either as a result of strabismus or another eye condition, such ascataracts (cloudy patches in the lens of the eye).
If a child only uses one eye to focus, their other eye will get weaker. If left untreated, the weaker eye could eventually lose all of its vision.
Treating strabismus and amblyopia
Strabismus and ambylopia can usually be treated by making the child wear a patch over their stronger eye. This forces their brain to start using the weaker eye, thereby making it stronger.
Glasses can also be prescribed to help balance the vision of both eyes. In more severe cases, surgery may be needed to realign or strengthen the muscles of the eye.