Before using cyclopentolate, tell your doctor or pharmacist if you are allergic to it; or to belladonna alkaloids (e.g., atropine); or if you have any other allergies. This product may contain inactive ingredients (such as preservatives like benzalkonium chloride), which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of personal or family history of glaucoma (angle-closure type), Down's syndrome, brain damageor spastic paralysis (in children), heart disease. After you apply this drug, your vision may become temporarily blurred. Do not drive, use machinery, or do any activity that requires clear vision until you are sure you can perform such activities safely. Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of eye medications for glaucoma/increased pressure in the eye (e.g., dorzolamide, pilocarpine), certain antiarrhythmic drugs (e.g., quinidine), antihistamines (e.g., diphenhydramine, meclizine), antispasmodics (e.g., dicyclomine), certain drugs for Parkinson's disease (e.g., anticholinergics such as benztropine, trihexyphenidyl), MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine), tricyclic antidepressants (e.g., amitriptyline). This medication may make your eyes more sensitive to light. Protect your eyes in bright light. Use dark sunglasses when outdoors.