Pupil reflex

• the muscles in the iris contract + relax to change the size of the pupil to control the amount of light allowed to pass in the eye - controlled by a reflex action
• when there’s a bright light, the pupil contracts and becomes smaller, reducing the amount of light entering the eye to prevent the retina from damaging, the radial muscles in the iris relax, the circular muscles contract
• when there’s a dim light pupils dilate to increase the amount of light entering the eye to produce a clearer image, radial muscles contract, circular muscles relax