Lenses

Intro to Lenses

November 29, 2023

1. ​Light enters the cornea

2. then the light goes through the pupil

3. the iris makes the pupil bigger to let more light in or smaller to let less light in.

4. light goes through the lens and focuses it on the retina.

5. The retina sends message to the brain through the optic nerve.

Introduction to Lenses

• Lenses are optical devices that focus or diverge light to form an image.

• They are used in various applications such as cameras, telescopes, and microscopes.

• There are two main types of lenses: convex (converging) and concave (diverging).

LENS, RETINA AND OPTIC NERVE

The light goes through the lens and make an image at the back of the retina. The image is upside down!!

The optic nerve transports the image to the brain and the brain flips the image.

• Lenses are optical devices that focus or diverge light.

• There are two types of lenses: concave and convex.

• Concave lenses are thinner in the middle and cause light rays to diverge.

• Convex lenses are thicker in the middle and cause light rays to converge.

Multiple Choice

What are the two types of lenses?

• Concave and convex

• Thick and thin

• Diverging and converging

• Optical and mechanical

Concave Lenses

• Thinner at the center

• they diverge light rays

• form virtual, upright and reduced images

• Used in nearsightedness correction.

  • **Diverge : to not come together, separate

Multiple Choice

What type of lenses are used in nearsightedness correction?

• Convex Lenses

• Concave Lenses

• Bifocal Lenses

• Progressive Lenses

Convex Lenses

• Convex Lenses:

  • Thicker at the center

  • they converge light rays

  • form real, inverted, and magnified images

  • Used in farsightedness correction

​Look at the first picture on the left, the ladybug picture is way past the retina.

​BEFORE AFTER
This person is able to see the ladybug correctly with their magnifier or glasses.

Multiple Choice

What type of lenses can correct farsightedness and magnify objects?

• Concave lenses

• Convex lenses

• Bifocal lenses

• Reading glasses

Multiple Choice

What is the job of concave lenses?

• To converge light rays

• To narrow the field of view

• To correct farsightedness

• To diverge light rays

Multiple Choice

What is the function of convex lenses?

• To diverge light rays

• To create magnified and upright images

• To correct nearsightedness

• To absorb light

Multiple Choice

What do convex lenses do?

• Converge light rays to a focal point

• Diverge light rays away from a focal point

• Absorb light rays and create darkness

• Reflect light rays in random directions