A researcher uses a flight simulator to investigate factors affecting pupil diameter.
One participant looks at a symbol on either a near display or a distant display. The light intensity at the participant's eye is adjusted. The same eye is measured after 120 seconds in each condition. Each pupil diameter is the mean of three repeats.
| Light intensity in lux | Distance of display from participant in m | Mean pupil diameter in mm |
|---|---|---|
| 20 | 0.5 | 6.2 |
| 400 | 0.5 | 2.6 |
| 20 | 5.0 | 6.0 |
| 400 | 5.0 | 2.5 |
Evaluate the conclusion that light intensity has a greater effect on pupil diameter than viewing distance.
102 exam-style questions on Edexcel GCSE Biology 2.4 The eye, covering 2.4.1 Structure and function of the eye and 2.4.2 Eye defects and their correction. Each one has a worked solution and a mark scheme showing where the marks go.