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.

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

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.