The right eyes of 45 patients will be treated by Biocarpine® and Vuity® eye drops. They will be considered as the case group,

The left eyes of the patients will be defined as the controls.

One millimeter of pilocarpine eye drop (Bakhtarbiochemistry Company, Iran) contains pilocarpine hydrochloride 1.25% (12.5 mg) as an active ingredient, equivalent to 1.06% (10.6 mg) pilocarpine free-base. The medication preservative is 0.0075% benzalkonium chloride. Inactive ingredients in the ophthalmic are boric acid, sodium citrate dihydrate, sodium chloride, purified water. Another pilocarpine eye drop was Vuity® (1.25% pilocarpine; Allergan company) contains the active intergradients of pilocarpine hydrochloride 1.25% (12.5 mg/mL), equivalent to 1.06% (10.6 mg/mL) pilocarpine free-base and the preservative agents was 0.0075% benzalkonium chloride.

The near vision will be measured based on the LogMAR vision at a distance of 33cm before and one hour after instillation of 1.25% pilocarpine eye drop.