Age-related cataracts are reported to be responsible for over 50% of world blindness and are considered a priority eye disease by the World Health Organization. Cataracts progress slowly and often have no subjective symptoms, so regular examination is required for early detection and treatment. We report on the design and development of a portable slit-light-based cataract detection device using near-infrared light and a scanning mirror. Imaging results were obtained by scanning cataract model eyes made from dimethylpolysiloxane and starch mixture and enucleated swine eye with induced cataracts. The fabricated system has adequate sensitivity to detect the smallest cataract formation and progress of cataract in the induced cataract eye and such measurements are useful for early detection of cataract. The results indicate that our fabricated slit-light device could be an easy-to-handle and low-cost tool for remote/routine detection and diagnosis of ocular diseases (like cataracts) without a need for an ophthalmologist.