1. The Eye

3. Eyelids Tear duct Cornea – skin that covers front of eye. Lets light pass into the eye. Iris – changes in size depending on light intensity. Pupil – an opening through which light passes Lens – focuses light onto the retina.

4. The Eye Retina – Has 2 vision receptors. One is sensitive to the colours of light, and the other to brightness Vision receptors join to Optic nerve - goes to the brain.

5. Converging and Diverging Lens Converging lens – the light comes together Diverging lens – this lens bends light rays outwards.

6. The Eye The lens in your eye acts as a converging lens and focuses light on the retina.

7. Converging and Diverging Lens The more curved the lens is, the more it bends the light rays ( think of thick glasses)

8. Problems with Eyes Long-sighted (far-sighted) Difficulty focusing on close objects eg when reading. The image focuses behind the eye. Glasses can be worn to correct the problem.

9. Problems with Eyes Short-sighted The focus of the image is in front of the retina. These people can focus on close objects, but have difficulty focusing on distant objects.

10. Problems with Eyes Colour-blindness – Cannot distinguish between certain colours – Eg people with red-green colour-blindness confuse certain shades of red, green and brown. – Inherited. – Incurable

11. Independent Task Go to Mr Leitchs weebly mrleitch.weebly.com Complete 1.0 ‘parts of the eye’ Functions of the parts Quiz