# A patient is diagnosed with a cataract in one eye. Explain how a cataract affects vision and describe how this condition can be treated.

> WJEC A-Level Biology (Wales) — 4.6 The nervous system · Explain · 5 marks

> A cataract is a condition that develops slowly and becomes more common as people age.

## Mark scheme (5 marks)

1. A cataract causes the lens to become cloudy
2. This is due to a build-up of protein in the lens
3. The cloudy lens restricts / reduces the amount of light passing through to the retina
4. This results in reduced / blurred / restricted vision
5. Treatment involves surgical removal of the cloudy lens / replacement of the lens / laser eye surgery to remove the cataract

## Key terms

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

## Related

- [Revision notes for WJEC A-Level Biology (Wales)](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/a-patient-is-diagnosed-with-a-a398b0db) · Published by Druglandscape Ltd.