Myopia (short sightedness) is a condition of the eye where the curvature of the cornea is steep or the axial length of the eyeball is long. When light enters the eye, it does not focus directly on the retina, but focuses in front of the retina. This causes the distance image a person sees to be out of focus.
Cases of short-sightedness can range from mild, where treatment may not be required, to very severe, which can significantly affect vision.
The symptoms of short-sightedness often start around puberty and get gradually worse until the eye is fully grown. Therefore it’s important to have regular eye examinations.
If you notice that distant objects seem to be fuzzy or your child is struggling to see things in the distance, such as the blackboard at school, you should arrange for a sight test with an optometrist (optician).
What causes short-sightedness?
Short-sightedness is a refractive eye condition. Refractive eye conditions are caused when problems with the structure of the eye affects how light rays enter your eye.
Most people are born slightly long-sighted (where close objects appear blurred) because their eyes haven’t grown to their full length. The eye then grows to their normal length, which should lead to the resumption of normal vision.
Generally, short-sightedness happens when the eye continues to grow and becomes too long from front to back As a result, light rays don’t reach the retina at the back of the eye. They only focus in front of it. This means that objects in the distance seem blurred.
Most cases of short-sightedness are caused by a combination of genetic and environmental factors that disrupt the normal growth of the eye.
There are three main treatment options for short-sightedness.
using corrective lenses, such as glasses or contact lenses, to compensate for the defect in the corneausing laser surgery – to correct the defect (laser surgery can’t be used in children because their eyes are still developing); most people will have to pay to have private laser surgeryimplanting an artificial lens into the eye to compensate for the longer eye length.
Hyperopia (long sightedness) is a condition of the eye where the curvature of the cornea is flat or the axial length of the eyeball is short. When light enters the eye, it does not focus directly on the retina, but focuses beyond the retina. This causes near images to appear out of focus and blurred.
If you are long-sighted, you will be able to see distant objects clearly, but nearby objects will be out of focus. Your eyes may also tire easily.
Read more about the symptoms of long-sightedness.
What causes long-sightedness?
Long-sightedness occurs when: The eyeball is too short.The cornea is not curved enough.
The cornea is the transparent layer at the front of the eye, and the lens focuses light on to the retina (the light-sensitive layer at the back of the eye).
There are various causes of long-sightedness including age, genetics and certain underlying medical conditions, such as diabetes (where there is too much glucose in the blood).
Children are sometimes born long-sighted. The problem usually corrects itself as the child’s eyes develop. However, it is important for children to have regular eyes tests because long-sightedness that does not correct itself can lead to other eye-related problems (see below).
Adults can also develop long-sightedness, which often becomes more noticeable after the age of 40. Age-related long-sightedness is known as presbyopia.
Read more about the causes of long-sightedness.
Refractive errors, such as long-sightedness, are usually identified during early eye examinations.
Your child will have their eyesight checked regularly as part of the routine screening programme. However, you can have their eyes tested at any time if you are concerned about their vision. Find your nearest optician.
Long-sightedness can usually be easily corrected, but if left untreated it could cause more serious complications that will affect your child’s vision permanently (see below).
Eye tests for children are free up until the age of 16.
Read more about NHS eye care services and diagnosing long-sightedness.
Long-sightedness is often corrected using either glasses or contact lenses. Several surgical techniques have also been developed to treat the condition. Laser surgery is sometimes used although it is not suitable for everyone but there are other treatment options available through London Eye Hospital that can be discussed at the free consultation.
Deepak J. Prasad