Revision of content and practise questions The eye Revision of content and practise questions

Objectives To be able to recall and label the features of the human eye (knowledge and synthesis) To be able to link our work on lenses to the function of the eye (applications) To be able to describe what is meant by long and short sightedness (comprehension) To be able to explain how lenses can be used to correct long and short sightedness (comprehension)

A quick recap…

Collaborative challenge time Your task is to make a 2D model eye. It should have different layers and colours, to differentiate the separate parts. It may have 3D elements. You must include the features appropriate for your group grade You have 10 minutes [a help sheet is available if very stuck!] Materials Pens Paper Scissors glue A/A* Retina Ciliary muscles Pupil Cornea Eye lens Iris Optic nerve Eye muscles Aqueous humour Vitreous humour B Retina Ciliary muscles Pupil Cornea Eye lens Iris Optic nerve Eye muscles C Retina Ciliary muscles Pupil Cornea Eye lens Iris You will need to remember to add a description of what each feature does!

Let’s have a look at each others….. Now you’ve seen some other group’s work, have another look at your own. ..\..\namespin 11T.ppt

Come around the front desk Far point and near point Near point = 25cm Far point = infinity

Short and long sightedness Short sighted Long sighted The eye is too long The image doesn’t focus far enough into the eye to hit retina Use a diverging lens to correct The eye is too short The image focuses to late/to far through eye Use converging lens to correct

Why does the pupil appear much wider in darkness than in daylight? A person reading a book looks up at a distant object. Explain what happens to the eye lens and why Explain what short sightedness is, and what you need to do to correct it. Explain why it works Explain what long sightedness is, and what you need to do to correct it. Explain why it works Explain what long sightedness is, and what you need to do to correct it. Explain why it works A student is unable to see a plate on a car 15m away with his left eye (which has a normal nearpoint). Is he long or short sited? Explain why. Why does the pupil appear much wider in darkness than in daylight? Why does the pupil appear much wider in darkness than in daylight?

Key points to learn!

Objectives Review What progress have you made towards the objectives? To be able to recall and label the features of the human eye (knowledge and synthesis) To be able to link our work on lenses to the function of the eye (applications) To be able to describe what is meant by long and short sightedness (comprehension) To be able to explain how lenses can be used to correct long and short sightedness (comprehension) What progress have you made towards the objectives? Are you more confident with ‘the eye’ work now? What are your main areas for development now?