The feeling of not seeing clearly occurs because the light rays coming parallel to the cornea and the lens cross fall short and do not reach the retina and in other cases are too long and passed with it. This type of problem causes defects in the lens system power we possess in our bodies (cornea and lens).
The power of these lenses is measured in diopters, which is the power of convergence and divergence of the lens, i.e., the ability to concentrate or separate the rays passing through them.
When the axis of the eye is shorter or few rays focus lens the image is formed behind the retina, and in this specific case we refer to farsightedness, the farsighted can not focus on nearby objects and alienate them, such as newspapers, magazines, books etc., focus to what they are seeing correctly, this type of problem is corrected with converging lenses or positive, if not treated can result in people who suffer from headaches, eye pain, especially after reading for a long time. (more…)