Page 21 - Science E-Book Prep.3 2024-2025 1st term_ unit 2_Neat

Science Department
Prep.3

How does the eye work?
1- Light rays fall on a body and reflected on our eyes.
2- Light rays refracted when passing through the cornea then the convex
lens of eye.
3- Refracted rays are collected in the retina forming a small, real and
inverted image.
4- Optic nerve transmits the image to the brain which re-correct it.

Notes:

? The diameter of the eyeball is the distance between the optical center
of the lens and the retina.

? To see clearly, the image must be formed on the retina.

The normal person can see clearly the:
-Near object at a distance not less than 25cm.
-Far objects at a distance up to 6m.

The most important of the vision defects:

-Short-sightedness and Long-sightedness

First Term 39