Optical Coherence Tomography (OCT) is a non-invasive images test. OCT uses light waves to take cross-section pictures of your retina. During the OCT testing, you will sit in front of the machine and rest your head on a support to keep it motionless. The equiptment will then scan your eye without touching it. Scanning takes about 5-10 minutes. If your eyes were dilated, they may be sensitive to light for several hours after the exam. OCT is useful in diagnosing many eye conditions, including: Glaucoma, Age-related Macular Degeneration, Diabetic Retinopathy and more.