THE LENS Transparent tissue
Biconvex
Changes shape in response to ciliary movement.
Focus near and far objects on the retina.
Thin Lens for distant objects
less refraction
Thick Lens Ciliary muscles contracted
more refraction
focus for close objects
IRIS The coloured part of the eye.
In front of the lens.
Has a hole in it called the PUPIL.
Made up of radial and circular muscle.
Radial muscle contracts - pupil enlarged
Circular muscle contracts - pupil size reduced.
Regulation of amount of light entering the eye.
eg., Bright sunshine - pin point pupil.
