The letters on your eye exam results tell the DMV what you can and cannot do behind the wheel

When you take the vision test at the DMV, the examiner records what you can see using letters or numbers on a chart. Those results get coded onto your license or your test paperwork using abbreviations — usually something like "20/40" or "corrected to 20/20" — and sometimes additional letters that describe restrictions or corrections you need. Understanding what these mean helps you know whether you passed, what happens next, and what you're legally required to do when you drive.

The most common notation is your visual acuity, written as a fraction like 20/20 or 20/40. The first number is always 20 — the distance in feet you stand from the chart. The second number is what a person with typical vision can read from that same distance. So 20/40 means you have to stand 20 feet away to read what someone with typical vision reads from 40 feet away. Your state's DMV has a minimum — often 20/40 or 20/50 — and if you don't meet it without correction, you'll need glasses or contacts to drive.

Key Takeaways

  • Visual acuity is recorded as a fraction like 20/20 or 20/40, and your state sets a minimum you must meet with or without glasses to get a license.
  • If you pass with glasses or contacts, your license will be marked to show you must wear correction while driving, and driving without it is illegal.
  • Some states use letter codes like "B" for bioptic telescopic lens or "H" for hearing impaired to note special devices or conditions affecting your driving.
  • If you fail the eye exam, you can usually retake it the same day or schedule another appointment, and many states let you bring your own glasses to test with.
  • Color blindness and peripheral vision problems are tested separately from visual acuity and may result in restrictions even if your 20/20 vision is fine.

How visual acuity numbers work and what they mean for your license

The fraction your examiner writes down describes how clearly you see. If you read 20/20, your vision is considered standard — you see at 20 feet what the average person sees at 20 feet. If you read 20/40, you're seeing at 20 feet what most people see at 40 feet, which means your vision is less sharp. Most states require you to see at least 20/40 in each eye, though some require 20/30 or better. A few states allow 20/50 or 20/60 if you pass other tests, but this varies.

The word "corrected" or "uncorrected" matters legally. If your results say "corrected to 20/20," it means you achieved that vision while wearing glasses or contacts. Your license will carry a restriction code — usually something like "corrective lenses required" or "must wear glasses" — and you are legally required to wear them every time you drive. Driving without the correction you tested with is a violation in most states, even if you feel fine without them. If you test uncorrected and pass, no restriction appears on your license.

Restriction codes and what letters on your license mean

Beyond the acuity number, your license or test results may show letter codes that describe how you can drive. These vary by state, but common ones include "B" for bioptic telescopic lens (a special magnifying device for low vision), "H" for hearing impaired, "L" for left eye only, "R" for right eye only, or "N" for no corrective lenses. Some states use "X" to mean daylight driving only, though this is less common for vision-related restrictions and more often tied to other medical conditions.

If your test shows you see better in one eye than the other, the examiner may restrict you to using that eye or require you to cover the weaker one while driving. This is rare but can happen if one eye is significantly worse or if you have a condition affecting one side of your vision. The restriction code on your license tells law enforcement and you what the requirement is. Ignoring a restriction code can result in a ticket and points on your record.

What happens if you fail the eye exam

If you don't meet your state's minimum vision requirement, you have options. Most DMVs let you retake the test the same day or within a few days at no extra cost. You can also bring your own glasses or contacts to the test if you think the ones you're wearing aren't your current prescription — the examiner will test you with them. If you fail again, you can visit an eye doctor, get a new prescription, and return to the DMV with updated glasses or contacts.

Some states accept a letter from an eye care professional (an optometrist or ophthalmologist) stating your corrected vision meets the standard. You bring this letter to the DMV instead of retesting. This route is faster if you know your prescription is current but the DMV test didn't go well. Check your state's DMV website to see whether they accept this option — not all do.

Color blindness and peripheral vision testing

Visual acuity is only one part of the eye exam. The examiner also tests your ability to see colors and your peripheral vision — what you can see to the sides without moving your eyes. Color blindness doesn't usually prevent you from getting a license, but the examiner records it. Peripheral vision problems are more serious: if you have a significant blind spot or can't see adequately to the sides, you may be restricted or denied a license, because you need peripheral vision to spot other vehicles and hazards.

These tests are quick — often a color plate test (you identify numbers hidden in colored dots) and a straightforward side-vision check where you watch for movement in your outer vision. If you have a known condition like glaucoma or retinitis pigmentosa that affects peripheral vision, tell the examiner before the test. They may ask you to see an eye specialist and bring documentation of your actual visual field before they issue or renew your license.

How to prepare for the eye exam and what to bring

If you wear glasses or contacts, bring them to the DMV. Wear them during the test if that's how you normally drive. The examiner will test you with them on. If you've recently changed your prescription, bring your new glasses or get new contacts before your test — the DMV tests your vision as it is on the day you take the exam, not as it was months ago.

If you're unsure whether your current prescription is still accurate, visit an eye doctor a week or two before your DMV appointment. This gives you time to get new glasses or contacts if needed and to feel confident in them before the test. If you fail the DMV eye exam and think it's because your glasses aren't right, ask the examiner whether you can retake it or bring a letter from your eye doctor — don't assume one failure means you can't get a license.

What to do if your license has an eye restriction you disagree with

If your license was marked with a restriction and you believe it's wrong, you can request a retest or ask for a medical review. Some states have a formal appeal process; others let you straightforward schedule another eye exam at the DMV. If you've had eye surgery or a new prescription since your last test, bring documentation from your eye doctor showing your vision has improved. The DMV will consider this when deciding whether to remove or modify the restriction.

Keep in mind that restrictions exist for safety — yours and others'. If you're restricted to daytime driving or required to wear glasses, following that restriction protects you legally and reduces your risk of an accident. If you genuinely believe the restriction doesn't reflect your actual vision, the fastest path is a visit to an eye care professional who can document your current vision and provide a letter to the DMV.

Frequently Asked Questions

Can I wear contact lenses instead of glasses if my license says "corrective lenses required"?

Yes. The restriction means you must wear some form of vision correction — glasses or contacts — while driving. It doesn't specify which. If you tested with glasses but prefer contacts, you can wear contacts instead, as long as your prescription is current and you see at least the minimum acuity your state requires.

What does 20/20 vision mean, and is it the best you can have?

20/20 means you see at 20 feet what the average person sees at 20 feet. It's considered standard vision and meets the requirement in every state. Some people test at 20/15 or better, which means they see more clearly than average, but 20/20 is the benchmark used for licensing.

If I fail the eye exam, can I still drive home from the DMV?

That depends on your state and why you failed. If you failed because you weren't wearing required correction, you should not drive without it. If you failed the test itself, check your state's rules — some states don't issue a license if you fail, while others let you drive on your old license while you retake the test. Ask the examiner before you leave.

Do I need to retake the eye exam every time I renew my license?

Most states require an eye exam at every renewal, though some allow you to skip it if your vision hasn't changed and you bring a letter from your eye doctor. Check your state's DMV website for the specific rule — it varies widely.

What if I have one eye that's much worse than the other?

The examiner tests each eye separately. If one eye doesn't meet the minimum, you may be restricted to using your better eye while driving, or you may need to wear correction in both eyes to meet the standard. Some states have specific rules about how much difference between eyes is allowed.