- Near objects – ciliary muscle contracts, slackening the suspensory ligament making the lense ‘fat’
- Distant objects – ciliary muscles relax, tensing the suspensory ligaments, making the lense ‘thin’
- Bright light – circular muscles contract, iris gets bigger so the pupil gets smaller. Less light gets into the eye
- Dark light – radial muscles contract, iris gets smaller, pupils get bigger, more light gets into the eye.
This is a paper 2, triple science fact.