How does the eye see and common vision problems.

To better understand the science of vision correction techniques, let’s first take a look at perfect vision that doesn’t need correction. Perfect vision comes when light beams meet at a point directly on the retina. If light rays fail to come to that point at exactly the same point, then sight becomes blurry. And so the purpose of restorative lenses/techniques is to refocus light rays so they do meet at that point on the retina.

Let’s look at faulty vision - what happens when those light rays do not arrive at that spot on the retina. There are a number of common eye/ visual disorders. Two of the most common are myopia, or short-sightedness, and hyperopia, or long-sightedness. People with myopia can see clearly up close but not at a distance. Those with hyperopia see better at a distance than at close range and occasionally experience difficulty bringing their vision into sharp, clear focus for reading and other near sight activities.

A few other well-known irregular eye conditions are astigmatism and presbyopia. A person with astigmatism has an irregularly-shaped cornea, which causes light rays to focus on two separate points in the eye. Presbyopia is commonly known as an “ageing eye”. In this condition the eye loses its ability to shift focus between far and near objects.
So these are the most common problems that could arise with individual’s sight. However, with advancing contact lens technology with many more options including eye exercises have been made available for treating each kind of problem.