Common vision problems
VISION PROBLEMS occur when the human eye in unable to focus light onto the retina with precision, resulting in a blurred vision. There are four types of focusing errors: short sightedness, long sightedness, astigmatism, and presbyopia.
Short sightedness (myopia)
People who have short sightedness (also known as short sightedness) can normally see nearby objects better than the distant ones. Nearsighted people can’t see certain objects with precision because their cornea and crystalline lens have too much focusing power for the eye length. Therefore, the light rays coming from objects far away are focused in front of the retina instead of onto it – whereas if the eye were shorter the rays would be focused exactly onto the retina. For more about laser treatment for myopia / short sightedness, read: Laser surgery for short sightedness.
Long sightedness (hyperopia)
long sightedness is the opposite of short sightedness, that is, people who have long sightedness see distant objects well but cannot see nearby objects precisely. In long sightedness, also called ‘hyperopia’, the rays of incoming light are focused behind the retina instead of onto it. This could be caused by either the eyeball being too small or by a weak focusing power. Therefore, long sightedness is an eye condition that results in a blurred vision, which can easily be corrected with the use of glasses or contact lenses. This type of focusing error is often hereditary, so people whose family members are farsighted are more likely to suffer from this eye disorder. Also, in children long sightedness can lead to strabismus, or ‘crossed eyes’. For more about laser treatment for long sightedness, read: Laser surgery for long sightedness.
Astigmatism (refractive error)
Astigmatism, which is often accompanied by short sightedness or long sightedness, occurs when the shape of the cornea is not symmetrical - as it should be – but abnormally curved, irregular and football-shaped. Therefore, astigmatism results in people’s eyes focusing incoming light rays not uniformly. People who have astigmatism experience out-of-focus vision for both near and far objects and they may sense that each one of their eyes sees objects in a slightly different way. Astigmatism is a common vision problem that can be also easily corrected with glasses or contact lenses. For more about laser treatment for astigmatism, read: Laser surgery for astigmatism.
Presbyopia (short arm syndrome)
Presbyopia is an eye condition resulting in the gradual loss of the eye's ability to adjust the focus from far to near that comes as we age. For this reason, presbyopia affects everyone as part of an aging process and gets worse over time, as the ability of the crystalline lens to focus precisely on nearby objects decreases progressively. Normally, presbyopia starts to appear between the ages of forty and fifty. The use of reading glasses or bifocals is normally enough to correct presbyopia, although their prescription needs to be changed as the eye disorder worsens. Symptoms include decreased capacity to focus nearby objects, headache and eyestrain. ‘Presbyopia’ is often confused with another eye disorder cited above, i.e. ‘long sightedness’, which however is not caused by a problem with the crystalline lens, but by a lack of focusing power that blurs the distance vision as well. For more about laser treatment for presbyopia, read: Laser surgery for presbyopia.