Retina scan (OCT)
OCT scan · optical coherence tomography · eye OCT · retina scan
A safe picture of the retina and the optic nerve, taken with light. You look into a machine, and nothing touches your eye.
For worse vision, wavy or bent lines, diabetes, glaucoma, or retina disease, and to track how treatment is working.
⏱ Duration: usually 5 to 15 minutes; if your pupils are widened, another 20 to 30 minutes of waiting
Be sure to tell your doctor
How to prepare
- Contact lenses. Contact lenses are taken out before the scan. Bring your lens case.
- Eyes. Do not wear mascara that day. It can get in the way.
- Pupils. Sometimes drops are used to widen your pupils. Then everything is blurry for a few hours. You cannot drive, so it is better to come with someone.
What to bring
- Your referral
- Your glasses
- Sunglasses, if your pupils will be widened
- Past OCT results, for comparison
How it goes
- If needed, drops are put in and you wait for the pupils to widen
- You sit, rest your chin on a support, and press your forehead against a bar
- You look at a glowing dot inside the machine
- Try not to blink for a few seconds while the picture is taken
- The same is done for the other eye
What you'll feel
- Nothing except bright light
- After pupil drops: blurry close-up vision, and bright light hurts your eyes
Afterwards
- Without drops, you can go back to your day right away
- After drops, vision usually returns to normal in 4 to 6 hours. Do not drive until then
- Images and a report are usually given the same day. An eye doctor reviews them
Contact a doctor straight away if
- Sudden loss of vision, flashes of light, or a curtain over your eye: see an eye doctor right away or call emergency services
Common questions
Is OCT harmful for the eyes?
No. The machine uses safe light, with no radiation. The scan can be repeated as often as needed.
Can I drive after an OCT?
If your pupils were not widened, yes. If drops were used, no, not until your vision is clear again, usually 4 to 6 hours.