# Explain how the eye focuses on a distant object and then refocuses to view a nearby object clearly. Include the role of the ciliary muscles and the lens in your answer.

> AQA A-Level Physics (7408) — 3.10.1 Physics of the Eye · Explain · 5 marks

## Mark scheme (5 marks)

1. When viewing a distant object, the ciliary muscles are relaxed
2. The suspensory ligaments are taut / under tension, pulling the lens flat / thin
3. A thin lens has a longer focal length / less power, so parallel rays from a distant object are brought to a focus on the retina
4. To view a nearby object, the ciliary muscles contract
5. The suspensory ligaments slacken / go slack, allowing the lens to become thicker / more curved, increasing its power / shorter focal length, so the image is focused on the retina

## Key terms

- [ciliary muscles](https://www.gradenine.co.uk/glossary/ciliary-muscles)
- [lens](https://www.gradenine.co.uk/glossary/lens)

## Related

- [Revision notes for AQA A-Level Physics (7408)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-the-eye-focuses-on-98f708c9) · Published by Druglandscape Ltd.