A cycloplegic eye drop will cause blurry vision from two hours to 48 hours depending on the strength used.
A cycloplegic eye drop is also used to help dilate the pupil so that a doctor can view the inside of the eye during an eye examination. This is done in order to view the overall health of the eye. Many dilating drops are primarily used to enlarge the pupil but have a side effect of cycloplegia, giving the patient the typical temporary blurry vision after an eye exam.
Cycloplegic eye drops are also used to help manage pain as treatment for certain diseases or conditions. When there is inflammation in the eye, the ciliary body may spasm, causing pain. Administering a cycloplegic eye drop will temporarily paralyze the ciliary body and calm the eye down to a level where the patient is much more comfortable.
A cycloplegic eye drop is also sometimes used after surgery to place the iris at rest during the healing process. Also, it may be important for an eye surgeon to keep the front part of the eye, the anterior chamber, well formed during the healing process. Cycloplegic drops are also helpful to manage post-operative inflammation.