An archivist examines documents held 25 cm from their eyes.
The nearest clear viewing distance is the shortest distance from the eyes at which an object can be seen clearly.
The archivist's results are shown in the table.
| Age in years | Lens placed in front of the eyes | Nearest clear viewing distance in cm |
|---|---|---|
| 35 | none | 18 |
| 50 | none | 30 |
| 65 | none | 62 |
| 65 | concave | 95 |
| 65 | convex | 22 |
Explain why the archivist's vision has changed and which type of lens should be used at age 65.
Use all the results in your answer.
135 exam-style questions on OCR GCSE Biology 3.1 Coordination and control – the nervous system, covering 3.1.1 Structure of the nervous system, 3.1.2 Coordinated response, 3.1.3 The reflex arc, 3.1.4 Structure of the eye, 3.1.5 Defects of the eye, 3.1.6 Structure and function of the brain, 3.1.7 Difficulties of investigating brain function, and 3.1.8 Limitations in treating nervous system damage. Each one has a worked solution and a mark scheme showing where the marks go.