Eye Defects-Lens-

-Retina-

By Daniel DrummondGraeme Paterson

Conor McHugh

Activity 1 – Aim:

•To find out where the light is focused in a normal eye

₪ Demonstration

₪Explanation

Activity 2 – Aim:

• To find out where light is focused in a short-sighted eye and find out how to correct this defect

₪ Demonstration

₪Explanation

Activity 3 – Aim:

• To find out where light is focused in a long-sighted eye and to find out how to correct this defect

₪ Demonstration

₪Explanation

You Should Now Know:

• That short-sighted people can see close objects but far away objects are blurred

• That long-sighted people can see far away objects but close objects are blurred

You Should Also Know:• That in short-sighted eyes, the light

rays are focussed to a point before they get to the retina

• That in long-sighted eyes, the light rays are not focussed to a point by the time they reach the retina and the focus would be behind the retina

You Should Also Know:

• That concave lenses are used to correct short-sight

• That convex lenses are used to correct long-sight