Cyclopentolate and phenylephrine relaxes muscles in your eye to dilate (widen) your pupil. Cyclopentolate and phenylephrine ophthalmic (for the eye) is used to dilate your pupil in preparation for an eye exam. Cyclopentolate and phenylephrine ophthalmic may also be used for other purposes not listed in this medication guide.
Cyclomydril is a medication used to widen the pupil just before eye surgery or an eye exam. Its purpose is therefore to dilate the eye. Cyclomydril is an anticholinergic as well as decongestant medicine. It acts principally by relaxing eye muscles, which results in a widened pupil. This action also ensures the eye does not focus on very near objects.