Defects of Vision
1) Conjunctivitis/Pink eye: It is the inflammation of the conjunctiva.
2) Myopia/Short-sightedness: It is a defect in which a person can see only those objects that are close to his/her eye. It produces blurred vision. It is caused due to elongation of the eyeball or thickened lens.
3) Hypermetropia/Far-sightedness: It is a defect in which a person cannot see nearer objects clearly but can see farther objects.
4) Astigmatism: It is a defect in which light rays do not converge at the retina and the vision becomes blurred. It is caused due to irregular lens or irregular retina.
5) Cataract: It is a disease in which the eye lens becomes opaque.
6) Glaucoma: It is a disease in which intraocular pressure is raised above normal level and loss of vision occurs gradually.
7) Presbyopia: It is a defect in which the lens is not able to focus images of nearer objects due to old age.
8) Colour blindness: It is the inability to recognize one or more colors due to deformity in cone cells.