Learning Objectives: Recognise and label a vertical section through the eye Understand their functions.

Learning Objectives:

• Recognise and label a vertical section through the eye

•Understand their functions

Draw a cross and a circle about 5 cm apart on a piece of paper. Hold the paper at arms length.

Close your left eye and with your right eye focus on the +. Then, slowly bring the paper closer to

your eye. The circle will seem to “disappear”. This is your blindspot.

• Eyesight provides the brain with more input than all the other senses combined!

• Each optic nerve contains one million nerve fibres

• It is estimated that more than half the information in the conscious mind enters through the eyes.

You have 30 seconds to memorise where each of the labels in the next

slide go

www.A6training.co.uk

End

Click on the eye diagram and see how much you learnt in 30 seconds!

N.B. This link will be active only within a school in Wales

IrisCorneaLens

RetinaSclera

Play the video. When watching, draw pictures to help you remember how light enters the eye. You will use your pictures after the video to explain the process to your partner. So … concentrate!

Cows eyes are very similar to human eyes,

just a bit bigger! So click on my eye to

watch a dissection!

Mooooooooo

Things near and far appear in focus

www.uniteforsight.org

Close up images like the chair are in focus, objects far away are blurry.

www.uniteforsight.org

• The eyeball is too long relative to the focussing power of the cornea and lens.

• Light rays are focused in front of the retina and the image is blurred.

• By putting spectacles with a concave lens, the light rays bend apart so that they are focused on the retina.

RetinaLight

rays

Concave lens

Objects far away are in focus, but close up objects like the chairs are blurry

www.uniteforsight.org

• The eyeball is too short relative to the focussing power of the cornea and lens.

• Light rays are focused behind the retina and the image is blurred.

• By putting spectacles with a convex lens, the light rays bend together so that they are focused on the retina.

RetinaLight

rays

Convex lens

This is a combination of both near and farsightedness, making all objects blurry

www.uniteforsight.org

• Corneal transplant is used when vision is lost because the cornea has been damaged by disease or injury.

• Some of the conditions that might require corneal transplant include the bulging outward of the cornea, a malfunction of the cornea's inner layer and painful corneal swelling or tissue growth on the cornea. Some of these conditions cause cloudiness of the cornea; others alter its natural curvature, which also can reduce vision quality.

WARNING… not for the faint hearted…

•Have our developments in eye surgery gone too far?

•How do you think this “eye tattoo” will effect his sight?

•Do you think it’s worth it?

Eye tattoo

• Can you recognise and label a section through the human eye?

• Do you understand their functions?

Learning outcomes