Health presents a great challenge for all nations. Improving the health of a nation’s citizens can directly affect the economic growth. Even developed countries, where government spend huge amount of money for establishing medical care units, are found more or less in the custody of various hazardous diseases. Similarly, developing countries particularly like India is facing widespread occurrence of non-communicable disease such as diabetes. Almost 60 million people are diabetic in India. According to the International Diabetes Federation (IDF), diabetes took 0.9 million deaths in 2015 in comparison to other non-communicable diseases. In order to combat the situation, healthy diet plan & physical activity followed by regular check- ups are required to prevent and control diabetes. If not, then the raised blood glucose concentration which is the main cause of diabetes imposes a severe damage to nerves & blood vessels. Among its effects, Diabetic Retinopathy (DR) is the common complication among 10-20% of diabetic subjects. An intervention of Computer Aided Design (CAD) & computer vision technique opens new dimension for medical practitioners in the diagnosis of various abnormalities. The main objective of this literature is to be acquainted with non-invasive methods or procedures for the determination of blood glucose level and screening of DR. Emphasis has been put on mentioning experimental data, applied methodology, clinical applications, and shortcomings.