Mydriatics are a type of medicine that make the pupil of the eye dilate (open up). Mydriatics also tend to relax the focusing muscles of the eye, which means that blurred vision is a common side effect.
Topical mydriatics are used during an eye examination to allow visualization of the retina and other structures deep within the eye. Mydriatics may also be used to treat inflammatory eye conditions such as iritis and cyclitis and to reduce cycloplegia (a painful paralysis of the ciliary muscle of the eye).
Mydriatics, such as tropicamide, relax the iris sphincter which is innervated by the parasympathetic nervous system. Other mydriatics, such as phenylephrine, dilate the iris through stimulation of alpha adrenoreceptors which are part of the sympathetic nervous system.
