Eye care guide
Understanding eye tests
Medical reviewer Mr Mohamed Mohyudin· Last recorded site review
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How long an eye exam takes
A standard sight test with history, vision charts and refraction often fits in 20 to 30 minutes. First visits, contact lens fittings or full dilated health checks can take 45 minutes or longer.
Common tests explained
Each part of the exam looks for different problems.
- Vision chart: measures clarity at distance and near
- Refraction: finds your glasses or contact lens prescription
- Eye pressure (tonometry): a quick puff or touch test for glaucoma risk
- Slit-lamp exam: magnified view of the front of the eye
- Retinal exam: looking at the optic nerve and blood vessels at the back
Why eyes are dilated
Dilating drops temporarily widen the pupil so the retina and optic nerve can be seen in detail. This helps detect glaucoma, macular disease and diabetic changes early. Side effects include light sensitivity and blurred near vision for several hours — bring sunglasses and avoid driving if unsure.
OCT and visual field tests
OCT (optical coherence tomography) is a non-contact scan of the retina's layers, useful for macular degeneration, glaucoma and diabetic eye disease. Visual field testing maps peripheral vision and is important in glaucoma monitoring. Neither usually hurts; OCT takes seconds per eye.
Frequently asked questions
How long does an eye exam take?
Most routine tests take 20 to 30 minutes. A first visit or full dilated exam with OCT or visual fields can take longer.
Why do opticians dilate your eyes?
Dilation lets them see the retina and optic nerve clearly to check for glaucoma, macular problems and diabetic changes. It temporarily blurs near vision and increases light sensitivity.
What is an OCT eye scan?
OCT is a quick, painless scan that images the layers of the retina. It helps detect and monitor conditions such as macular degeneration, glaucoma and diabetic retinopathy.
Trusted sources
For general background, these organisations provide eye-health information. This list is further reading, not a record that they reviewed this article.