Disorders of the eye.
• Astigmatism• Myopia - nearsightedness• Hyperopia - farsightedness• Presbyopia• Color blindness• Cataracts• Glaucoma• Conjuctivitis
Astigmatism• Distortion of vision due to abnormal curvature
of the cornea or lens• Lenses can correct astigmatism
QuickTime™ and a decompressor
are needed to see this picture.QuickTime™ and a
decompressorare needed to see this picture.
Myopia (nearsightedness) • Common among
young people - eyeball grows too rapidly during maturation & light is focused in front of the retina
• Can be corrected with the use of concave lens
Hyperopia(farsightedness)
• Light is focused behind the retina– Eye may be too
short
• Can be corrected with a convex lens
Presbyopia
• Declining ability to accommodate
• Bifocals• People who never
needed glasses before may need convex lenses for reading
Color Blindness
• X linked trait; most often affects males
• Inability to distinguish between certain colors
Cataracts• Loss of transparency
caused when the lens becomes cloudy
• More common in older people
• Can be treated with surgery
Glaucoma
• Increased pressure on the optic disk due to build up of aqueous humor
• This can be treated one of two ways– Surgery of the Iris– Drugs that constrict the
pupil
Conjunctivitis
• May be caused by smoke, dust, chlorine, bacteria, and viruses
• Most common in children may be treated with antibiotics