The two main defects of the human eye are myopia, which is nearsightedness, and hyperopia, which is farsightedness; both myopia and hyperopia can be treated by wearing glasses. Another major defect is when the curvature of the cornea is irregular: this condition is called astigmatism. Astigmatism can be treated by wearing glasses or undergoing surgery.
Some other disorders of the eye are listed below:
Conjunctivitis is commonly referred to as pink eye. This happens when the conjunctiva that covers the cornea and that lines the eyelids is irritated due to an allergy or being sick.
Amblyopia is also known as having a lazy eye. This happens when the brain prefers one eye over the other. Amblyopia may happen for a number of reasons, such as strabismus which causes one or both eyes to turn inward. Amblyopia has been known to run in families. There are many ways to treat amblyopia, such as glasses, surgery, eye drops and wearing a patch to strengthen the eye muscles.
Glaucoma is caused by the deterioration of the optic nerve. There are several things that can cause this disorder, such as lack of certain vitamins, genetics and gender. Glaucoma can be treated with surgery or special eye drops.
Cataracts can be caused by a protein buildup that makes the eye lens cloudy. There are a few things that cause cataracts, such as age, trauma to the eye and medical conditions such as diabetes. Cataracts are normally treated with surgery but can also be treated by wearing bifocal lenses.