To prepare you for an OCT exam, your ophthalmologist may put dilating eye drops in your eyes. These drops widen your pupil and make it easier to examine the retina. You will sit in front of the OCT machine and rest your head on a support to keep it motionless. The equipment 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.