The Eye

LO: To know the structure and function of parts of the eye and how the lens allows us to focus on objects

Optical Illusions:

The EyeLook at the diagram showing the main parts of the eye

Label the eye below:

Parts of the eye:Part Function

Ciliary Muscles

Cornea

Lens

Iris

Pupil

Retina

Suspensory Ligaments

Focussing and Range of Vision

How does your focus change if you look up from a book and look out of the window at a distant object?

The thickness of the lens is controlled by the ciliary muscles.

When you focus on a near object they contract, squeezing the lens and making it thicker.

When you change your focus to a far object the ciliary muscles relax and the lens becomes thinner.

What is the range of vision of a normal human eye?25cm to infinity

Near point: 25cmFar point: Infinity

This means we can see clearly any object that is within these distances.

How the lens works:

Summary

1a) The front of the pupil is protected by the …. b) The pupil if the eye is at the centre of the ….. c) The ….. of the eye foccuses light onto the ……2) A person with normal eyesight looks up from a book and observes a distant object.Describe what happens to the shape of the lens.