What are the Most Common Problems with Vision?
Most people will at some point in their lives experience vision problems. Age is probably the biggest precipitating factor in common eye problems. Most of the common problems that are associated with vision are actually refractive errors. Refractive errors can take the form of any of several ailments, including farsightedness, nearsightedness, presbyopia and astigmatism. These errors occur as a result of an irregular eye-shape that makes it difficult for images to focus properly on the surface of the retina. There are several ways through which this can happen. The eyeball can be longer or shorter than normal; the lens can become stiff or clouded with age, the shape of the cornea might be irregular and so on. You might be surprised to learn that most people have one or several of these conditions already. That’s why eye problems are so common.
What does ‘Refraction’ Mean?
Many people confuse the term ‘‘refraction’’ with ‘‘reflection.’’ Although the two terms are optically-related, they, nevertheless, refer to two different things. The term ‘refraction’ is perhaps more common in the field of Physics. In technical terms, it means the slowing down of light as it enters a more optically dense medium from a less optically dense one. In everyday life, it manifests in the apparent bending of objects when placed in a container that’s half full of water. Additionally, objects that are placed in water appear to be closer to the surface than they really are.
Light rays are bent as they pass from the outside world into our eyes through the cornea and lens. This bending of light rays plays a very crucial role as it helps the rays to become focused on the retina. The retina converts these light signals to electrical signals which are then relayed to the brain through the optic nerve. The brain interprets these signals and identifies them as the objects we see. When refraction in our eyes is defective, problems arise. These problems can include:
1. Nearsightedness – this is also referred to as myopia. People who suffer from this condition can see nearby objects clearly, while far away objects appear blurry. This happens when the eye ball is too long, resulting in light being focused before it reaches the retina.
2. Farsightedness – this is referred to as hyperopia. This happens when the eye ball is too short which results in light being focused behind the retina. As a result, objects that are far-placed appear clear while near-placed objects appear blurry. Farsightedness is more complex and can manifest in different ways in different people. People with this condition can sometimes go unnoticed when young, but vision problems when viewing both near and far objects when older, are experienced.
3. Astigmatism – astigmatism is caused by an uneven cornea that results in light being refracted at different rates, thus failing to be focused accurately on the retina. People with astigmatism see objects as stretched out and blurry.
4. Presbyopia – this condition is age-related and results in difficulty in seeing nearby objects. This is caused by a stiff lens that fails to change in shape in order to accurately focus light from nearby objects.
Who is at Greatest Risk?
Presbyopia affects mostly adults 35 years and over. Other types of refractive errors can happen in both children and adults. Refractive errors tend to be inherited and can be passed on from parents to children through genetic means.
Signs and Symptoms
The most common problem associated with refractive errors is blurred vision. Others include:
- Double Vision
- Eye Strain
Diagnosis of Refractive Errors
Eye care professionals diagnose refractive errors by performing a dilated eye examination. Sometimes people are unaware that their vision is below par, until a visit to the optometrist with an exam is completed.
Treatment of Refractive Errors
Refractive errors are treated using eye glasses, contact lenses, and through surgery if very serious.Leave a reply