By Michael Walach – Bio
Our eyes allow us see by taking in light and processing it into signals to our brains. The light is refracted (bent) by the eyes in this process. If the refraction is not perfect, then our vision is impaired.
There are three types of eye refraction errors:
- myopia (nearsighted)
- hyperopia (farsighted)
- astigmatism (uneven refraction)
Myopia is where the eyes bend incoming light rays too much, causing nearby objects to be clear, but distant objects appear blurred. By wearing glasses, we move the eye’s focus point farther away, allowing us to see far away items more clearly.
In the case of Hyperopia we have the opposite problem. The eyes, do not bend incoming light enough, causing distant objects to be clear, but nearby ones to appear blurred. By wearing glasses, we move the eye’s focus point closer, allowing us to see nearby items more clearly. In hyperopic eyes, the glasses add extra power to the eye by placing a magnifying lens over the eye.
The hyperopic eye has to work harder to see up close than it does far away. Young children and adults (still having the ability to change the shape of their lens) can often see near and far, even if they are hyperopic.
The third problem is astigmatism. The eyes bend light slightly differently in one direction than they do in another, usually because the the cornea (front surface of the eye) is slightly oval, rather than perfectly round.
Sometimes eyes with astigmatism also have myopia or hyperopia. By wearing corrective eye glasses, all three of these common conditions can be well corrected in most cases.