Cataract is a major preventable cause of childhood visual impairment and blindness worldwide. Good visual outcomes may be achieved with early surgical intervention, in conjunction with appropriate optical correction and aggressive occlusion therapy. Red reflex is an easy, simple, cheap, and valuable screening test for early detection of vision abnormalities such as cataracts, glaucoma, retinoblastoma, retinal abnormalities, systemic diseases with ocular manifestations, and high refractive errors. Most cataracts are congenital, but some cataracts may not be manifest at birth. A positive red reflex at the beginning of life can become negative, so red reflex test should be performed regularly during the first two years of life. In this article, we present an infant diagnosed as galactokinase enzyme deficiency in the third month of life with positive red reflex test.