Lens

What type of lens is a convex lens?

A converging lens.

What is another name for a convex lens?

A positive lens.

What vision problem does a convex lens correct?

Hyperopia or farsightedness.

What type of lens is a concave lens?

A diverging lens.

What is another name for a concave lens?

A negative lens.

What vision problem does a concave lens correct?

Myopia or nearsightedness.

What is the Optical Center (O)?

The center of the lens where light rays pass without being refracted.

What is the Principal Axis?

The line that passes through the optical center.

What is the Center of Curvature (C)?

The center of the sphere of which each lens surface is a part.

What is the Focal Point (F)?

The point where refracted parallel rays meet or appear to diverge from.

Object Location: Infinity (very far away)

Image Formed: Real, Inverted, Small

Image Location: At F₂

Object Location: Beyond 2F

Image Formed: Real, Inverted, Small

Image Location: Between F₂ and 2F₂

Object Location: At 2F

Image Formed: Real, Inverted, Equal size

Image Location: At 2F₂

Object Location: Between 2F and F

Image Formed: Real, Inverted, Large

Image Location: Beyond 2F₂

Object Location: At F

Image Formed: No finite image; refracted rays are parallel

Image Location: At infinity

Object Location: Between F and O

Image Formed: Virtual, Upright, Large

Image Location: Behind the Object

Object Location: In front of a concave lens

Image Formed: Virtual, Upright, Small

Image Location: Between O and F, same side as the object