The Eye

The Eye By Josh and Amy

Focusing The eye focuses by using the lens and the cornea, how it focuses is: by making the lens thicker and thinner.

A labelled diagram of the eye

Long and short sight • Long sight – eyeball is too short and the lens is long and thin. It can be corrected by a convex lens. • Short sight – eyeball is too long and the lens is thin and flat. It can be corrected by a concave lens.

Eye accomodation • The ciliary muscles and suspensory

ligaments in the eye change the shape of the lens. When the lens is thicker, more light is refracted in the eye. As we get older the muscles and ligaments become less flexible.

Red – green colour blindness • Is when no red or

green cell they are missing. This is an inherited condition

Sex

      Colorblind      

    Normal  Vision    

Male

XoY

X+Y

   Female    

XoXo

X+X+    X+Xo

Tests for colour blindness •

This image contains the number 37, although someone who is protanopic might not be able to see it. Protanopic is when there is no red photoreceptors at all.