OBJECTIVEOBJECTIVE

IDENTIFY TYPES OF CORRECTIVE LENSES USED TO CORRECT SIGHT

PROBLEMS[COS 5, SAT 10]

OBJECTIVEOBJECTIVE

IDENTIFY TYPES OF CORRECTIVE LENSES USED TO CORRECT SIGHT

PROBLEMS

CORRECTIVE CORRECTIVE LENSESLENSES

EYE GLASSESCONTACTS

CONVEX LENSESCONVEX LENSES

DEFINITION:

Convex Lenses are corrective lenses used to help those who are farsighted.

CONVEX LENSESCONVEX LENSES

Convex lenses are thicker in the middle than at the edges.

When light passes thorough a convex lens, the rays bend toward each other.

Glasses or contacts with convex lenses magnify the print, allowing these people to read more easily.

FARSIGHTEDNESS 

                                                         

FARSIGHTEDNESSFARSIGHTEDNESS

Farsightedness, is a focusing problem, which occurs when the cornea is not curved enough, or the eye is shorter than normal. The reduced length means the light rays focus behind the retina, producing a blurred image.

FARSIGHTEDNESFARSIGHTEDNESSS

CONCAVE CONCAVE LENSESLENSES

DEFINITION:Concave Lenses

are corrective lenses used to help those who are nearsighted.

CONCAVE CONCAVE LENSESLENSES

Concave lenses are thicker around the edges than in the middle.

When light passes through a concave lens, they bend away from each other.

These lenses bend outward just enough to make distant objects seem closer.

NEARSIGHTEDNESNEARSIGHTEDNES

SS   In a nearsighted person the cornea is too

steep or the eye is too long and the focal point is in front of the retina resulting in blurred distance vision.

For a farsighted person the focus of the eye is behind the retina. People who are farsighted can have trouble seeing at distance.

Using Contact Lenses

Contact Lenses

Like eyeglasses, contact lenses change the path of light. But with contact lenses, concave lenses are used for

both nearsighted and farsighted people. Because contact lenses are so close to the eye, they don’t need to be thick to

bend the light enough to correct a person’s version.

OBJECTIVEOBJECTIVE

IDENTIFY TYPES OF CORRECTIVE LENSES USED TO CORRECT SIGHT

PROBLEMS

CORRECTIVE CORRECTIVE LENSESLENSES

EYE GLASSESCONTACTS

Convex and Concave Lenses