Understanding common eye tests
Learn what four common tests involve before your appointment. Your eye-care team chooses which tests you need and explains your results.
General education · Clinician review pending. This guide does not interpret your results or replace your clinic’s instructions.
Dilated eye exam
Eye drops widen your pupils, the openings that let light into your eyes. This gives the clinician a better view inside the eyes to check for disease.
What to expect
Dilation may be one part of an exam that also checks vision and eye pressure. After the drops, vision can be blurry and light may feel uncomfortable for a few hours. Arrange for someone to drive you home. Bring sunglasses if you have them.
Ask your clinician: Will my eyes be dilated today, and what should I plan for afterward?
OCT scan
Optical coherence tomography, usually called OCT, uses light to make detailed images of eye structures, including the retina at the back of the eye. Clinicians can compare scans over time to look for changes.
What to expect
You sit still and look at a target while the images are taken. The scanner does not touch your eye or puff air at it. The scan usually takes a few minutes. Ask the clinic how long to allow for the whole appointment and whether other tests are planned.
Ask your clinician: What part of my eye are you checking, and who will explain the scan results?
Visual-field test
This checks vision across the area you can see, including straight ahead and to the sides. It helps clinicians assess and monitor conditions affecting vision.
What to expect
In a common computer-based test, you rest your chin and forehead on supports, look at a central target, and press a button when you notice a light. Some lights are deliberately very faint; you are not expected to see every one. Blink normally and tell the technician if you need help or feel uncomfortable.
Methods and timing vary. A repeat test may help check reliability or track changes.
Ask your clinician: Which type of test will I have, and will I need it repeated?
Eye-pressure test
Tonometry measures pressure inside the eye. It is one of the checks used when assessing glaucoma.
What to expect
The method may use a brief puff of air or an instrument that gently touches the eye. For applanation tonometry, which uses a touching instrument, the clinician first uses numbing drops. Your clinic can explain which method it uses.
Take the result to your clinician for an explanation alongside the rest of your eye exam. This guide does not provide a personal pressure target.
Ask your clinician: How does this measurement fit with my other test results, and what follow-up do I need?
Source: MedlinePlus: glaucoma tests
Source links checked September 27, 2026. This is a source check, not clinical approval. Independent clinician review is still pending.
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