What not to do before an eye test?

Editorial team Published on

Avoid wearing contact lenses right before your appointment, as they can temporarily alter the shape of your cornea and affect test accuracy.

What to Avoid Before an Eye Exam

  • Wearing Contacts: Remove your contact lenses a few hours or even a full day before your test (follow your Urban Optics or doctor's specific guidelines).
  • Excessive Screen Time: Limit phones, computers, and intense reading right before the exam to prevent eye strain and fatigue.
  • Too Much Caffeine or Alcohol: Skip heavy caffeine and alcohol, which can raise your blood pressure or dry out your eyes and skew pressure readings.
  • Eye Makeup: Avoid heavy mascara, eyeliner, or eyeshadow on the day of the exam to keep products away from your eyes.
  • Rushing Your Schedule: Leave your schedule open if you expect your eyes to be dilated, and bring sunglasses for the bright trip home.

How many hours of sleep before eye check up?

You should aim for at least 7 to 8 hours of uninterrupted sleep before an eye check-up.

Why Sleep Matters

  • Reduces Eye Strain: Being well-rested prevents dry, tired eyes that can make testing uncomfortable or harder to focus on.
  • Ensures Accuracy: Extreme fatigue can slow your pupil response and affect focus, making it harder to give clear answers during subjective vision tests. (Though users on Mayo Clinic Connect generally agree that minor tiredness won't ruin an exam, as doctors account for it, being rested helps).

Quick Tips to Prepare

  • Limit screens: Avoid heavy phone, computer, or TV use for a few hours before the exam to reduce temporary eye fatigue.
  • Skip caffeine: Avoid coffee or energy drinks right before your appointment, as they can elevate your blood pressure and alter results.
  • Bring essentials: Pack your current glasses, contact lenses (with cases), and sunglasses in case your eyes are dilated.

What makes you fail an eye exam?

You fail an eye exam when your vision or eye health falls below specific legal, medical, or functional standards.

Common Causes of Failure

  • Refractive errors: Conditions like nearsightedness (myopia), farsightedness (hyperopia), or astigmatism make it hard to read standard distance charts.
  • Poor visual acuity: Scoring worse than required thresholds—such as failing to reach 20/40 clarity for a standard driver's license—causes a failure.
  • Limited visual field: Losing side (peripheral) vision prevents you from meeting the 110-degree field requirement for driving.
  • Eye diseases: Conditions like cataracts, glaucoma, macular degeneration, or retinitis pigmentosa block light, damage optic nerves, or destroy retinal cells.
  • Temporary fatigue: Severe tiredness, instrument myopia (focusing strain inside a testing device), or uncorrected eye strain can lower short-term test scores.

Health Conditions Detected

An American Academy of Ophthalmology comprehensive exam can also reveal non-eye health issues through blood vessel and nerve changes:

  • Diabetes and high blood pressure
  • High cholesterol and heart disease
  • Brain tumors or aneurysms pressing on optic pathways

How to pass an eye vision test?

To pass an eye vision test like the DMV Vision Test, you need to meet the minimum visual acuity standard of 20/40 (with or without corrective lenses) by preparing your eyes and following basic exam rules.

Preparation Tips

  • Wear corrective lenses: If you need glasses or contacts to see far away, wear them during the test. If you pass with them, your license will require you to wear them while driving.
  • Update your prescription: Make sure your current glasses or contacts are up to date so you do not experience blurriness.
  • Rest your eyes: Avoid long hours of screen time right before your test to prevent temporary eye strain.
  • Get enough sleep: Being well-rested helps you focus and keeps your vision sharp during the exam.

During the Test

  • Don't squint: Squinting can distort letters and make your vision harder for the examiner to accurately assess.
  • Blink normally: Keep your eyes lubricated by blinking naturally so the letters on the chart don't blur.
  • Follow instructions closely: Cover the correct eye when asked and look straight ahead at the target.

Is it better to have an eye exam in the morning or afternoon?

Scheduling an eye exam in the morning is generally better because your eyes are well-rested, hydrated, and free from the digital eye strain that builds up throughout the day.

Why Morning is Preferred

  • Less Fatigue: Your ciliary muscles (the focusing muscles in your eye) are fresh and not tired from computers, phones, or reading.
  • Less Dryness: Eyes tend to dry out as the day progresses from screen use and environment, which can slightly alter prescription measurements.
  • Glaucoma Screening: Eye pressure is often highest in the morning, making it an ideal time if your doctor is checking for glaucoma.

When Afternoon Works Fine

  • Routine Checks: Any time of day is fine for a standard, routine eye exam if you feel comfortable.
  • Busy Schedules: If you cannot find an early slot, an afternoon appointment is completely effective as long as you rest your eyes beforehand.

7 Eye Exam Tips for Better Vision, Glasses and Overall Experience

9 related questions found

What is the best time of day to have an eye test?

The best time of day for an eye exam is in the morning when your eyes are well-rested and less prone to digital strain or fatigue.

Best Time of Day

  • Morning: Ideal if you have dry eyes, need precise refraction testing, or are being screened for glaucoma, as inner eye pressure tends to measure highest early in the day.
  • Afternoon: Perfectly fine for routine updates or regular prescription checks if your schedule requires it, though your eyes may feel more tired after a long day of work or screens.

How Often to Get an Eye Exam

According to the American Academy of Ophthalmology, the recommended timeline depends on your age and health:

  • Adults under 40: Every 5 to 10 years if healthy and asymptomatic.
  • Ages 40 to 64: Every 2 to 4 years (or more often if you wear corrective lenses or have high risk factors).
  • Ages 65 and older: Every 1 to 2 years.
  • High-risk groups: Annually if you have diabetes, high blood pressure, or a family history of eye disease.

Is there anything I shouldn't do before an eye exam?

Avoid wearing contact lenses to your exam and skip caffeine or alcohol to ensure accurate test results.

What to Avoid Before an Eye Exam

  • Wear contact lenses: Contacts can temporarily change the shape of your cornea and cause dry eyes. Switch to glasses a few hours or a day prior depending on your doctor's advice.
  • Consume caffeine and alcohol: Coffee, soda, and alcohol can raise your blood pressure, alter eye pressure readings, and cause dry eyes.
  • Overuse digital screens: Staring at phones, computers, or TVs right before your appointment can cause digital eye strain and fatigue.
  • Forget sunglasses: You will need them if your doctor dilates your pupils, as your eyes will be sensitive to light.

What damages your eyesight the most?

Chronic systemic conditions like unmanaged diabetes and lifestyle factors like smoking cause the most severe, permanent damage to eyesight.

Major Threats to Vision

  • Unmanaged Systemic Diseases: Conditions like diabetic retinopathy damage blood vessels in the retina and stand as a leading cause of blindness. High blood pressure also harms ocular blood vessels over time.
  • Smoking: Tobacco use significantly accelerates the development of blinding conditions, including macular degeneration, cataracts, and glaucoma.
  • Ultraviolet (UV) Exposure: Skipping UV-blocking sunglasses allows harmful solar radiation to damage the cornea and lens, leading to cataracts and tissue growths.
  • Severe Physical Trauma: Blunt force or chemical splashes from sports or DIY projects can cause sudden retinal detachments or globe ruptures without proper protective eyewear.
  • Severe Infections: Sleeping or swimming in contact lenses introduces dangerous microbes that trigger corneal ulcers and permanent scarring.

Can optometrists tell if you're lying?

Optometrists can often tell if you are faking or exaggerating your vision test results, but they cannot read your general thoughts or detect everyday lies.

How They Catch Faked Eye Tests

During an eye exam, doctors use several built-in methods to spot inconsistencies:

  • Objective instruments: Tools like an autorefractor measure your eye's focusing ability automatically without needing your input.
  • Cross-checking: Doctors compare results from different tests. If your chart answers do not match the physical shape and health of your eyes, inconsistencies stand out.
  • Repetition: Asking you to compare lenses multiple times or changing testing distances quickly reveals patterns if you are guessing randomly or exaggerating.

General Dishonesty

Eye doctors have no special training or equipment to tell if you are lying about unrelated topics. Their equipment measures eye structures and light refraction, not truth or deception. For regular eye care, sharing honest feedback helps ensure your prescription is accurate.

Can you drive if you fail an eye test?

You cannot legally drive if you fail an official state vision screening and your license is denied, suspended, or restricted until your eyesight meets required standards.

What Happens When You Fail

  • No immediate loss: Failing the initial test at a licensing office does not automatically mean permanent revocation.
  • Referral: The agency typically gives you a vision report or certificate to take to an eye doctor.
  • Restrictions: If you pass only with corrective lenses, your license gets a restriction requiring you to wear glasses or contacts while driving.
  • Denial or revocation: If your vision cannot be corrected to meet the minimum threshold (usually 20/40 or 20/200 depending on the state and type of restriction), you will be deemed unqualified to drive.

Next Steps

  • Schedule an appointment with an optometrist or ophthalmologist for a comprehensive exam.
  • Get an updated prescription for glasses or contact lenses.
  • Submit the signed Visual Examination Report or state form back to your local driver licensing office to re-evaluate your driving status.