# A student is reading a book held close to their face. They then look up and focus on a distant tree through the window. Explain the changes that occur in the eye to bring the distant tree into focus on the retina.

> Pearson Edexcel A-Level Biology A (9BI0) — 4.4 Vision and hearing · Explain · 5 marks

## Mark scheme (5 marks)

1. The ciliary muscles relax when focusing on a distant object
2. The suspensory ligaments become taut / tight / under tension
3. The lens becomes less curved / thinner / flatter
4. This refracts (bends) light less / by a smaller amount
5. So that light from the distant tree is focused onto the retina / a sharp image forms on the retina

## Key terms

- [retina](https://www.gradenine.co.uk/glossary/retina)

## Related

- [Revision notes for Pearson Edexcel A-Level Biology A (9BI0)](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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-is-reading-a-book-bf12005c) · Published by Druglandscape Ltd.