Diabetic retinopathy is an eye disorder that affects people who have diabetes. Diabetic retinopathy occurs when high blood sugar levels harm the blood vessels in the eye. These blood vessels tend to swell and leak. They also can close, preventing blood from flowing through. Irregular new blood vessels are formed on the retina and eyesight becomes weak and blurred. Diabetic retinopathy can affect people with any type of diabetes (type 1, type 2, or gestational diabetes). Therefore, it is vital to detect diabetes retinopathy at an early stage. In this paper, we outlined the idea of diabetic retinopathy and highlighted the relevance of its methodologies, along with an exhaustive comparative study that helped us to shortlist the best performing model. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.