National Registry of Certified Medical Examiners

Vision - 49 CFR 391.41(b)(10)

Federal Motor Carrier Safety Regulation (FMCSR)

49 CFR 391.41(b)(10) - Summary of Regulation

"A person is physically qualified to drive a commercial motor vehicle if that person —

Has distant visual acuity of at least 20/40 (Snellen) in each eye without corrective lenses or visual acuity separately corrected to 20/40 (Snellen) or better with corrective lenses, distant binocular acuity of at least 20/40 (Snellen) in both eyes with or without corrective lenses, field of vision of at least 70º in the horizontal meridian in each eye, and the ability to recognize the colors of traffic signals and devices showing standard red, green, and amber."

  • The required tests measure visual acuity, peripheral horizontal visual fields, and color.
  • Visual acuity is measured in each eye individually and both eyes together.
    • Distant visual acuity of at least 20/40 (Snellen) in each eye, with or without corrective lenses.
    • Distant binocular visual acuity of at least 20/40 (Snellen) in both eyes, with or without corrective lenses.
  • Field of vision of at least 70° in the horizontal meridian in each eye.
  • Color vision must be sufficient to recognize traffic signals and devices showing the standard red, amber, and green traffic signal colors.
  • When corrective lenses are used to meet vision qualification requirements, the corrective lenses must be used while driving.
  • A medical examiner, ophthalmologist, or optometrist may perform and certify vision test results. The medical examiner determines driver certification status.
  • Monocular vision is disqualifying.

Driving and Public Safety

Adequate central and peripheral vision are necessary for safe driving.

The driver must perceive the relative distance of objects, and react appropriately to vehicles in adjacent lanes or reflected in the mirrors, to pass, make lane changes, and avoid other vehicles on the road.

The visual demands of driving are magnified by vehicles that have larger blind spots, longer turning radiuses, and increased stopping times.

Health History

Here are the vision questions that are asked in the health history. Yes responses require clarification and documentation.

  • Eye disorders?
  • Impaired vision (do not include corrective lenses)?

Here are important vision questions to ask.

  • Symptoms related to or caused by eye diseases?
  • Use of ophthalmic preparations that have side effects that can affect safe driving?

Physical Examination

Examine the eyes for:

  • Pupillary equality.
  • Reaction to light and accommodation.
  • Ocular motility.
  • Ocular muscle imbalance.
  • Extraocular movements.
  • Nystagmus.
  • Exophthalmos.

Note abnormal findings. Discuss the value of regular vision examinations in early detection of eye diseases.

Ask about:

Medical examiners cannot diagnose these diseases or conditions because most do not have the equipment necessary to diagnose them.

Required Tests

Required vision screening tests include central visual acuity, peripheral vision, and color vision.

Central visual acuity

The Snellen chart or the Titmus Vision Tester measure static central vision acuity. The requirement for central distant visual acuity is at least 20/40 in each eye and distant binocular visual acuity of at least 20/40. Test results must be recorded in Snellen-comparable values. 

Eyeglasses or contact lenses may be worn to meet distant visual acuity requirements. When corrective lenses are worn to meet vision qualification requirements, corrective lenses must be worn while driving.

Snellen Distant Acuity Test.

Peripheral vision

The requirement for peripheral vision is at least 70° in the horizontal meridian for each eye. In the clinical setting, some form of confrontational testing is often used to evaluate peripheral vision. When test results are inconclusive, the evaluation should be performed by a specialist with equipment capable of precise measurements.

Recommended Protocol for Screening the Visual Field.

Color vision

The color vision requirement is met by the ability to recognize and distinguish among red, amber, and green, the standard colors of traffic control signals and devices. True color perception is not required.

Additional Evaluation and/or Ancillary Tests

Eye trauma and ophthalmic disease can adversely impact visual performance and interfere with safe driving. Some ophthalmic diseases are seen more frequently with increased age or are secondary to other diseases such as diabetes mellitus or atherosclerosis.

The clinical setting may not provide the necessary equipment to evaluate ophthalmic diseases adequately. The medical examiner determines if the vision symptoms and signs or underlying disease require evaluation by an ophthalmologist or optometrist. The medical examiner then considers the documented results and the specialist opinion when determining if the vision meets qualification requirements.

Select Ophthalmic Diseases

The following links are summaries of medical report recommendations for vision:

FMCSA medical reports are available from the FMCSA Web site.

Certification and Documentation

The qualified driver meets all of the following requirements:

  • Distant acuity of at least 20/40 in each eye,
  • Binocular acuity of at least 20/40,
  • Horizontal field of vision of at least 70° measured in each eye, and
  • The ability to recognize and distinguish among traffic control signals and devices showing standard red, amber, and green colors.

The medical examiner may certify the driver for up to 2 years. 

The driver who wears corrective lenses to meet the vision qualification requirements must wear corrective lenses while driving. The medical examiner marks the "wearing corrective lenses" checkbox on both the Medical Examination Report form and the medical examiner's certificate. The examiner should advise the driver to carry a spare set of eyeglasses. The driver avoids both stress and delay when lost or damaged eyeglasses or uncomfortable contact lenses can be replaced immediately.

Monocular vision

Monocular vision occurs when the vision requirements are met in only one eye, with or without the aid of corrective lenses, regardless of cause or degree of vision loss in the other eye. In low illumination or glare, monocular vision causes deficiencies in contrast recognition and depth perception compared to binocular vision. Monocular vision is disqualifying.

The medical examiner should complete the certification examination of the driver with monocular vision and determine if the driver is otherwise qualified. The driver with monocular vision who is otherwise qualified may want to apply for a Federal vision exemption.

The otherwise medically qualified driver with a Federal vision exemption

At the annual recertification examination, the driver presents a valid vision exemption and a copy of the specialist eye examination report before receiving the medical examiner's certificate.

Certify the driver for up to 1 year. Mark the "accompanied by" exemption checkbox and write "vision" to identify the type of Federal exemption.

The otherwise medically qualified driver applying for a Federal vision exemption

The driver applying for a vision exemption should include a copy of the Medical Examination Report form and the medical examiner's certificate with the application to the Federal Vision Exemption Program.

Certify the driver for up to 1 year. Mark the "accompanied by" exemption checkbox and write "vision" to identify the type of Federal exemption. Provide the driver with a copy of the Medical Examination Report.

The medical examiner does not issue a Federal vision exemption. Both the medical examiner's certificate and Federal vision exemption are required before the driver with monocular vision can legally drive a commercial vehicle in interstate commerce.

Federal Vision Exemption Program

Find this page at: http://nrcme.fmcsa.dot.gov/sensory_system_vision.aspx