Application of light-emitter in medicine is of environmental advantages as a tool in photodiagnosis and phototherapy. Therefore, progresses in optical technology has revealed the opportunities of light-emitting materials in advancement of clinical operations and research. Devices such as light emitting diodes (LEDs) and organic light emitting diodes (OLEDs) has been a fundamental sources of light of different colour which applied to medical diagnosis and therapy due to their significant improvements in stability, efficiency, and brightness achieved from recent research work. Therefore, light-emitting materials has shown valuable opportunities in medical photodiagnosis and phototherapy achievable by various experimental research and machine learning. Though many of challenges has been addressed for essential development of future LEDs and OLEDs for biomedical applications. This work described the importance of light-emitting materials in biomedical applications with the opportunities in medical treatment and challenges of utilization of light-emitter in medical treatment.