Eye Disease
Refractive
Lens Exchange Surgery
Hyperopia is a sight problem
that affects your ability to see close-up objects. Commonly
known as long-sightedness, the condition is a type of
focusing error, and tends to get worse as you get older.
Long-sightedness occurs when
the eyeball is too short in relation to the focusing
power of the cornea and lens. This means that light
rays travel to the back of the retina before they have
been bent by the cornea and lens. Close-up objects therefore
appear blurry because the light rays have not been focused
properly. Long-sighted children often find it easy to
see distant objects clearly, because the lens is flexible
in young eyes and able to focus easily. As you get older,
it becomes more difficult to focus, and the way that
you see distant objects may also be affected.
Long-sightedness is most common in older people, and
does not generally become a problem until middle-age.
Children's eyes are very flexible, and they are often
able to compensate for long-sightedness by focusing
the lens. Long-sightedness in children may therefore
become apparent through a lack of interest in small
objects, and difficulty in reading or following stories.
If you suspect your child may be long-sighted, it is
important to get treatment as soon as possible to prevent
them developing crossed eyes. Left untreated, young
children who are long-sighted may eventually lose vision
in one eye.
The symptoms of long-sightedness
are similar in adults, and you will notice difficulty
in reading, writing, and conducting other detailed tasks.
You may also find you are unable to view the information
on a computer screen clearly. If you perform a lot of
close work and find you are getting eye-strain or headaches,
this may indicate an excessive effort to focus the eyes,
which could be due to long-sightedness.
Long-sightedness can occasionally run in families, and
it is therefore important that children under three
are formally tested for the condition if there is a
family history. Other than genetic factors, there are
rarely definite causes for long-sightedness. Rarely,
hyperopia may be caused by conditions that indent and
shorten the eyeball, such as orbital tumors behind the
eye.
It is very important that you visit your optician every
two years, particularly if you are over the age of 40.
Regular eye check-ups will identify long-sightedness
early on so that corrective treatment can be administered.
A simple test that involves reading
letters from a chart is used to test your sight. The
letters become progressively smaller on each line of
the chart. If you have taken the test before and have
previously been prescribed glasses or contact lenses,
then your optician may want you to take the test while
wearing your glasses or contact lenses.
If you can only read the top
line of the eye chart, you may be eligible to register
as blind or partially sighted. You will need to be referred
by an eye doctor who will carry out further tests and
write to you local social services department confirming
that you have been diagnosed as blind or partially-sighted.
You may also be registered as blind or partially-sighted
if you can read the first three lines of the chart but
have a very restricted field of vision.
An eye specialist will also look
for signs of eye conditions such as glaucoma and diabetic
retinopathy, by shining a light into your eyes to see
how well they react to light.
If you are diagnosed as long-sighted, it is likely that
you will be prescribed glasses or contact lenses to
correct your vision. It is usually necessary for your
optician to conduct further tests to work out exactly
what kind of glasses you need. You may be asked to wear
special lenses to look at various charts containing
different letters or colours.
After further examination, an
eye doctor will discuss the results with you and your
best course of action. They will give you a prescription
for the type of glasses or contact lenses that you need
to wear, which you can use at any optician.
Long-sightedness can be corrected
with a convex lens that ensures light rays fall on the
retina and focus accurately. The lens of the eye becomes
less flexible with age, which is why you may need to
increase the strength of your prescription as you get
older. If your ability to focus is significantly reduced,
you may need to wear two different pairs of glasses.
Alternatively, some people use varifocal or bifocal
lenses in order to see objects clearly that are both
close up and far away. Long-sighted children with a
squint need to be monitored carefully to avoid a lazy
eye (amblyopia) developing.
Long-sightedness can also
be treated more permanently with Lasik surgery.
