Funduscopy is an examination of the back part of the eye’s interior (fundus). Also known as ophthalmoscopy, it can help detect damage that is the earliest sign of diabetes in some patients. It features an instrument called a funduscope (or ophthalmoscope), which contains a mirror and lenses that are used to examine the inside of the eye. It is performed to look for damage caused by diabetic retinopathy or other eye diseases.

Using this procedure, the physician can examine the fundus, which is composed of the:

• Retina. The light-sensitive nervous tissue lining the inner eye and connected to the brain via the optic nerve. The central part of the retina that produces sharp, central vision is known as the macula.
  
  
• Optic disc. The end of the optic nerve, viewed on cross section, where it enters the eye. Because there is no retina where it enters the back of the eye, it creates a blind spot in the retina. The brain normally learns to ignore this area of the retina without vision.
  
  
• Choroid. Dark-brown vascular coat of the eye between the sclera (tough, white, fibrous outer envelope of tissue covering most of the eye) and the retina.
  
  
• Blood vessels.

Funduscopy may be performed as part of a dilated pupil exam. Regular examination of the eyes is crucial to the long-term health of people with diabetes. A person with diabetes is 25 times more likely to become blind than a person who does not have diabetes, according to the American Academy of Ophthalmology. Other tests may also be performed, such as tonometry, which measures the pressure inside the eye, and perimetry, which assesses peripheral (side) vision