Short-sightedness, also known as ‘myopia’ or ‘near-sightedness’, makes it difficult to focus on objects in the distance.
Myopia is a common refractive error. Nearsighted people see things best when they are close up but have trouble seeing things that are farther away. Myopia occurs when light entering the eye comes into focus in front of the retina instead of precisely on the retina.
This can be caused by a cornea that is too steeply curved, by an eye that is too long, or by a combination of both problems.
People with mild to moderate myopia can see things close-up, but people with severe myopia may only be able to see objects clearly when they are just a few inches away.
Symptoms of short-sightedness
If objects in the distance appear blurry it could be a sign that you suffer from short-sightedness. Close up vision is generally unaffected in people with myopia; however, in very severe cases of short-sightedness, close-up vision can also become blurry.
Short-sightedness may make it difficult to recognise faces at a distance and driving can become more difficult too. In children, short-sightedness can often be recognised when they have difficulty seeing the blackboard in their classroom or watching television from a distance.
Short-sighted people may also suffer from headaches and tired eyes from over-straining them. Frowning and squinting are also common symptoms of short-sightedness.
Causes of short-sightedness
Short-sightedness is a refractive error caused by an imperfection in the eye. The imperfection changes the way your eye focuses the light rays that pass into it. This can happen when:
- The eyeball is longer than normal
- The cornea is more curved than normal
When any of these imperfections occur it changes the focusing point of the eye so that light rays focus in front of your retina, instead of on it. This makes objects in the distance look blurry. Close-up objects generally still appear clear, because the light rays enter your eye at a slight angle, so they focus on your retina properly.
Myopia, is believed to be an inherited condition, so you are more likely to be short-sighted if one or both of your parents are short-sighted too. There is also some evidence to suggest that short-sightedness is more common in people who do a lot of close up work, such as reading and using a computer.
Treatment for short-sightedness
Myopia, or nearsightedness, can be diagnosed easily by your eye care professional. Treatments for myopia are designed to change the way that light rays are bent when they enter the eye so that they come into a point of focus precisely on the retina.
Refractive errors are often corrected using either glasses or contact lenses. However, for permanent vision correction and freedom from the hassles of glasses and contacts, there are several surgical techniques such as laser eye surgery to treat the condition.
Myopia can also be treated by implanting a prescription lens inside the eye where it works with the rest of the eye’s natural focusing system to refocus light rays precisely on the retina. When myopia causes distant objects to appear blurry, any of these treatments can restore clear vision, making daily activities much easier.