Clinical Focus on Eye Disorders

Question 1

-Eyeball too long, image is focused in front of the fovea.
Or caused by a cornea that is too round (steeply curved)— Refractive power of cornea is too strong, convergence occurs in front of the fovea.

Answer 1

Myopia/Nearsightedness

Question 2

-Eyeball too short, image is focused behind the fovea.

Or caused by a cornea that is too flat—Refractive power is too weak, convergence occurs behind the fovea.

Answer 2

Hyperopia/Farsightedness

Question 3

Farsightedness usually caused by aging of the eye. Crystallines accumulate in the lens, causing it to lose flexibility and have difficulty focusing for near vision.

Answer 3

Presbyopia

Question 4

Cornea is aspheric or has an asymmetric curvature. Image fails to fall on the fovea as a result.

Answer 4

Astigmatism

Question 5

Aqueous humor fails to drain properly, causing pressure to build and shut off the blood flow to the retina and optic nerve. Death of neurons in both structures
causes blindness.

Answer 5

Glaucoma

Question 6

Lack of aqueous humor causes the lens to degenerate and turn opaque (milky/cloudy) due to insufficient nutrients. Also caused by diabetes mellitus, excessive UV
radiation exposure, heavy smoking.

Answer 6

Cataracts

Question 7

Hole develops in center of the visual field; Exact etiology unknown but linked to age, smoking, obesity, high cholesterol, genetics.

Answer 7

Macular Degeneration

Question 8

Decreased blood circulation in retina causes retinal death or dislocation, producing blindness. Other causes of retinal detachment besides diabetes: Shrinking of vitreous humor with age; severe blow to head.

Answer 8

Diabetic Retinal Degeneration or Detachment

Question 9

A.k.a. “Pinkeye.” Most often a viral infection of the conjunctiva, the
membrane that lines the eyelids.

Answer 9

Conjunctivitis