Eye exam: what to expect
A comprehensive eye exam is simple and painless. You read an eye chart, look through lenses to find your prescription, have your eye pressure checked, and often get drops that widen your pupils so the doctor can see the back of the eye. Your eye doctor decides what the results mean for you. (NEI, 2025) (AAO, 2024) (MedlinePlus)
Eye pain, an eye injury or infection, or sudden floaters or flashes of light need a call to an eye doctor right away, not a routine appointment. (AAO, 2024)
Who does it and who should go
The exam is done by an ophthalmologist or an optometrist; both are often called an eye doctor. (MedlinePlus) Sources differ on routine checks for people with no symptoms:
- USPSTF: for adults 65 and older without symptoms seen in primary care, the evidence is insufficient to weigh the benefits and harms of vision screening (I statement, 2022). It does not apply to people who notice vision problems or have vision loss from a condition such as diabetic retinopathy. (USPSTF, 2022)
- AAO: a complete exam every 5 to 10 years before 40 if your eyes are healthy, and every year or two from 65. (AAO, 2024)
- NEI: a dilated eye exam every 1 to 2 years if you are over 60, African American and over 40, or have a family history of glaucoma; most people with diabetes or high blood pressure need one at least once a year. (NEI, 2025)
The USPSTF looked at screening by primary care, not at seeing an eye doctor. The full schedule by age is on eye exams by age.
How to prepare
- Bring your glasses or contact lenses. (MedlinePlus)
- Be ready to talk about any vision problems, your general health, the medicines you take and eye disease in your family. (AAO, 2024) (MedlinePlus)
- Plan for someone to drive you home in case your pupils are dilated, and bring sunglasses. (NEI, 2025) (MedlinePlus)
- For contact eye-pressure tests that use dye, contact lenses come out first, because the dye can stain them. (MedlinePlus)
What happens during the exam
- Visual acuity: you cover one eye and read letters on a chart, usually 20 feet away, that get smaller line by line. Near vision may be checked with a card about 14 inches from your face. (MedlinePlus) (AAO, 2024)
- Refraction: you look at the chart through a device with different lenses (a phoropter) and say which looks clearer. This finds your glasses or contact lens prescription. (AAO, 2024) (MedlinePlus)
- Pupils, eye movement and side vision: a light checks how your pupils react, you follow an object with your eyes, and you say when you see things off to the side without moving your eyes. Loss of side vision can be a sign of glaucoma and can happen without you noticing. (NEI, 2025) (AAO, 2024)
- Eye pressure (tonometry): a quick puff of air, or a tip that gently touches the eye after numbing drops. It does not hurt; the air puff may feel like brief, mild pressure. (NEI, 2025) (MedlinePlus)
- Slit lamp: a microscope with a light looks at the front of the eye, including the eyelids, cornea, iris and lens, for cataracts, scars or scratches. (AAO, 2024)
- Dilation: drops widen your pupils so the doctor can look at the retina and optic nerve. This is how diabetic retinopathy, glaucoma and age-related macular degeneration are checked. (NEI, 2025) (AAO, 2024)
- Other tests you may have: retina photos (fundus photos), optical coherence tomography (OCT) scans of the back of the eye, a color vision test with dotted cards, or an automated visual field test. (AAO, 2024) (MedlinePlus)
The AAO says the exam should take no more than 45 to 90 minutes, and parts of it may be done by a staff member. (AAO, 2024)
After dilation
For a few hours your vision may be blurry and you may be sensitive to light. (NEI, 2025) MedlinePlus says the drops usually wear off in several hours and, in rare cases, can cause an attack of narrow-angle glaucoma, dizziness, dry mouth, flushing, or nausea and vomiting. (MedlinePlus) Tell your eye doctor if anything feels wrong.
What the numbers mean
Visual acuity is written as a fraction. The top number is how far you stand from the chart, usually 20 feet. The bottom number is how far away a person with normal vision could stand and still read the same line. Missing one or two letters on a line still counts as reading that line. (MedlinePlus)
| Result | What it means |
|---|---|
| 20/15 | Sharper than average: you read at 20 feet what the average person reads at 15 feet. (AAO, 2025) |
| 20/20 | Normal (6/6 in meters): you read at 20 feet what the average person reads at 20 feet. It is not "perfect" vision. (AAO, 2025) |
| 20/40 | You read at 20 feet what a person with normal vision reads from 40 feet. In most states this is the cutoff for an unrestricted driver's license. (AAO, 2025) |
| Worse than 20/40 with glasses | What the USPSTF counts as impaired visual acuity. (USPSTF, 2022) |
| 20/200 or worse with glasses | The level at which a person is called "legally blind". (AAO, 2025) |
- With or without glasses: acuity is recorded uncorrected (without glasses or contacts) and best corrected (with the best prescription). The driving and legal blindness levels above refer to vision with glasses or contacts. (MedlinePlus) (AAO, 2025)
- How common 20/20 is: an AAO ophthalmologist says about 35% of adults have 20/20 without glasses, contacts or surgery, and about 75% with correction. (AAO, 2025)
- Eye pressure: MedlinePlus gives 10 to 21 mm Hg as the normal range. Corneal thickness changes the reading, so the doctor may measure it (pachymetry). A high reading can have causes other than glaucoma, such as inflammation or injury. (MedlinePlus)
- A normal exam means normal acuity, color vision, full side vision, eye muscles that work together, normal eye pressure and normal eye structures. (MedlinePlus)
If you need glasses or contacts, you may get a prescription. If the doctor finds signs of an eye disease, you talk about the next steps together. (NEI, 2025) This page does not recommend any treatment or product. See also after an abnormal screening result.
If you have diabetes
The ADA advises a first dilated, comprehensive eye exam at diagnosis of type 2 diabetes and 5 years after onset of type 1. If one or more yearly exams show no retinopathy and glucose is in the goal range, every 1 to 2 years may be considered. Programs that use retina photos read remotely, or FDA-approved software, are also suitable ways to screen, with a path to a full exam when needed. (ADA, 2026) More on screenings if you have diabetes.
Cost and coverage
Medicare does not cover routine eye exams for glasses or contact lenses; some Medicare Advantage plans add vision benefits. (Medicare.gov) Part B covers an eye exam for diabetic retinopathy once a year if you have diabetes. (Medicare.gov) It covers a glaucoma screening every 12 months if you are at high risk: you have diabetes, a family history of glaucoma, are African American and 50 or older, or Hispanic and 65 or older. You pay 20% of the approved amount after the deductible. (Medicare.gov) For private plans, see preventive screenings covered by insurance.
Questions people ask
How long does an eye exam take?
The American Academy of Ophthalmology says a comprehensive eye exam should take no more than 45 to 90 minutes. If your pupils are dilated, your vision may stay blurry and light-sensitive for a few hours afterward. (AAO, 2024) (NEI, 2025)
Can I drive after a dilated eye exam?
The NEI and MedlinePlus advise asking someone to drive you home, because your vision may be blurry for a few hours. Bring sunglasses; your eyes may be sensitive to light. (NEI, 2025) (MedlinePlus)
What does 20/40 vision mean?
Standing 20 feet from the chart, you read the line a person with normal vision can read from 40 feet. 20/20 is normal, not perfect: some people see 20/15. In most states 20/40 or better is needed for an unrestricted driver's license. (MedlinePlus) (AAO, 2025)
What is a normal eye pressure?
MedlinePlus gives 10 to 21 mm Hg as the normal range. Corneal thickness changes the reading: thick corneas read higher and thin corneas lower, so a corneal thickness test (pachymetry) may be needed. Your eye doctor explains your number. (MedlinePlus)
Does Medicare cover a routine eye exam?
No. Medicare does not cover routine eye exams for glasses or contact lenses. Part B covers a diabetic retinopathy exam once a year if you have diabetes, and a glaucoma screening every 12 months if you are at high risk. (Medicare.gov) (Medicare.gov) (Medicare.gov)