The retinal pigment epithelium (RPE) is a single layer of cells located between the neurosensory retina and the choroid in the eye. This layer plays a crucial role in maintaining the health and function of the retina by providing support, nourishment, and waste removal for the photoreceptor cells. The RPE is also involved in the visual cycle, the process by which light is transformed into electrical signals that can be processed by the brain. Research on the retinal pigment epithelium focuses on understanding its role in various eye diseases, such as age-related macular degeneration, retinitis pigmentosa, and diabetic retinopathy. Scientists are investigating how dysfunction or damage to the RPE contributes to these conditions, as well as potential therapeutic strategies to protect or repair the RPE in order to preserve vision. Studying the RPE is essential for developing treatments and interventions to prevent or slow the progression of these blinding diseases.