There are two main eye defects and they include Myopia Also known as nearsightedness a person suffering from this disease is only able to see objects near the eye clearly. It is believed that most of the people who wear spectacles are patients of myopia. The disease can be caused due to two reasons. One of them is the lens might be too thick and fails to focus light rays coming from distant objects onto the retina and also it be a result of maller eye ball. On the other hand, Hypermetropia Also known as 'hyperopia. A person with this defect only able to see objects far from the eye clearly. Unlike in the above defect, Hypermetropia is more prevalent among the old people. Hope this can explain defects. Good luck.
