Amblyopia is the most common cause of visual impairment by prevalence about 1-5 % of the total population. As a Definition, amblyopia is decrease in visual acuity without any visible structural damage in eyes. Despite such definition of amblyopia, many studies demonstrate that Amblyopia cause damage to other visual functions too. If amblyopia is diagnosed and treated early in life, in most cases will lead to increase visual acuity to normal levels But if the treatment be postponed after 7 to 8 years of age (critical period) clinically is considered incurable due to lack of sufficient plasticity. Untreated amblyopia can cause vision loss and even blindness and can affects personal and professional abilities. Because of the increasing effect of Fluoxetine on neuronal plasticity, use of it in treatment of amblyopia was considered by the authors of this study. In this study, the effect of Fluoxetine in the treatment of amblyopia after the critical period, and various aspects of visual functionwas assessed , including contrast sensitivity, Stereopsis and impact of Fluoxetine on VEP latency at 15 and 60 minute. For this purpose, a total of 35 patients, age range 11 to 37 years on drug and placebo groups were categorized and Treatment was applied for 90 days. In both groups occlusion of healthy eye for 4-6 hours a day with eye activities such as reading , watching TV and video games was considered. Visual acuity, contrast sensitivity, stereopsis and VEP was assessed before and after treatment. In both groups visual acuity, contrast sensitivity and stereopsis improved after treatment. More VA improvement was seen in Fluoxetine group (0.24 log MAR) compare to placebo (0.12 log MAR). VEP latency for 60 minute, improved to normal levels in both groups, but only in Fluoxetine group for 15 minute.