A patient with glaucoma who has been using timolol (Timoptic) drops for several days tells the nurse that the eye drops cause eye burning and visual blurriness for a short time after administration. The best response to the patient's statement is

Patients should be instructed that eye discomfort and visual blurring are expected side effects of the ophthalmic drops but that the drops must be used to prevent further visual-field loss. The temporary burning and visual blurriness might not lessen with ongoing use, are not relieved by avoiding systemic absorption, and are not symptoms of glaucoma.