What effect do mydriatics have on the eye?

Mydriatics are medications specifically designed to cause dilation of the pupils, a process known as mydriasis. When these drugs are applied, they work primarily by relaxing the muscles of the iris that control pupil size. This dilation allows for better examination of the interior of the eye during an ophthalmic examination, enabling doctors to assess the retina and other structures more effectively.

The effect of pupil dilation can also improve visual function in certain situations, particularly in low light, as larger pupils allow more light to enter the eye. However, the primary and defining effect of mydriatics is their ability to cause the pupils to expand. This is why choosing dilation as the correct answer highlights the fundamental action of mydriatic agents, distinguishing them from other types of ocular medications that may have different uses or mechanisms.