Researchers based at the Department of Ophthalmology, Seoul National University College of Medicine, Korea, suggest that preliminary results from an investigation of the feasibility of using a colour vision test to screen for diabetic macular edema may be useful for detecting and monitoring the progression of pathology. Early diagnosis of diabetic macular edema is expected to provide clinicians with opportunities to intervene as early as possible in order to preserve functional vision with a number of treatments, including the recently effective range of anti-VEGF therapies.