Blindness due to diabetes mellitus is potentially preventable in the majority of patient. Early detection of sight-threatening changes is associated with a better outcome, indicating the need to screen for retinopathy. At least 50% of diabetic patients do not attend a hospital, so that diabetologists and ophthalmologists are unable to screen the diabetic population comprehensively. Although in theory all patients has access to general practitioners, these may lack training or confidence to screen for retinopathy. Hospital based or community optometrists using direct ophthalmoscopy or slit lamps and technicians performing fundus photography are alternatives which may be more effective. Further studies are required to examine the effectiveness of optometry screening. Initial studies using fundus photography raised concerns about the sensitivity of the technique, but these have been partially addressed by improvements in methodology and technology. As well as technicological effectiveness, factors affecting patient uptake of screening services still need to be addressed.