Visual Defects

Short-sightedness

-Light rays focus in front of the retina

-Caused by eyeball being too convex

-Treated with concave lenses

Long-sightedness

-Light rays focus behind the retina

-Caused by the eyeball being too concave

-Treated with convex lenses

Astigmatism

-Light rays not focused evenly on the retina

-Caused by cornea or lens is not equally rounded in all directions

-Treated with prescription lenses, contact lenses, laser therapy

Cataracts

-Clear transparent lens becomes cloudy, prevents light entering

-Cataracts develops and increases in size slowly over time

-Treated by surgery

Short-sightedness Defect

Short-sightedness Treatment

Long-sightedness Defect

Long-sightedness Treatment

Normal vs. Astigmatism

Normal vs. Cataracts