Understanding Nearsightedness and Farsightedness

The video explains the differences between nearsightedness (myopia) and farsightedness (hyperopia). Nearsightedness occurs when the eyeball is too long, causing distant objects to appear blurry. It is corrected with concave lenses that spread light rays before they reach the eye. Farsightedness happens when the eyeball is too short, making nearby objects blurry. Convex lenses are used to correct this by bending light rays towards each other before they reach the eye. The video concludes with a summary of these vision problems.

What is another term for nearsightedness?

• Astigmatism

• Myopia

• Hyperopia

• Presbyopia

What causes nearsightedness?

• Eyeball is too short

• Eyeball is too long

• Lens is too thick

• Lens is too thin

Which type of lens is used to correct nearsightedness?

• Cylindrical lens

• Bifocal lens

• Convex lens

• Concave lens

How do concave lenses help in correcting nearsightedness?

• They make light rays converge

• They increase the length of the eyeball

• They make light rays diverge

• They focus light on the cornea

What is another term for farsightedness?

• Myopia

• Hyperopia

• Astigmatism

• Presbyopia

What causes farsightedness?

• Lens is too thick

• Lens is too thin

• Eyeball is too short

• Eyeball is too long

Which type of lens is used to correct farsightedness?

• Cylindrical lens

• Bifocal lens

• Convex lens

• Concave lens

How do convex lenses help in correcting farsightedness?

• They focus light on the cornea

• They decrease the length of the eyeball

• They make light rays converge

• They make light rays diverge