Physical Qualification Standards and Advisory Criteria - Vision Flashcards
What regulation states the physical qualifications for drivers?
49 CFR 391.41
What are the standards for vision?
Distant visual acuity of at least 20/40 in each eye w/o corrective lenses OR visual acuity separately correct to 20/40 or better with corrective lenses
Distant binocular acuity of at least 20/40 in both eyes w or w/o corrective lenses
Field of vision of at least 70deg in the horizontal meridian in each eye
The ability to recognize the colors of traffic signals and devices showing standard red, green, and amber
When corrective lenses are used to meet vision qualification requirements…
The corrective lenses must be used while driving.
Who can perform and certify vision test results?
A medical examiner, ophthalmologist, or optometrist
BUT, the medical examiner determines driver certification status
Is monocular vision allowed?
No, monocular vision is disqualifying.
What should you look for on physical exam of the eyes?
Pupillary equality Reaction to light and accommodation Ocular motility Ocular muscle imbalance Extraocular movements Nystagmus Exophthalmos
What are the required tests for vision?
Central visual acuity (Snellen)
Peripheral vision
Color vision
The Snellen wall chart should be ___ feet away from the driver.
20 feet
What is the denominator in teh snellen test result?
The number of the last line of type the driver can read accurately
If a test other than the snellen is used for central vision acuity, you must…
Record the test results in Snellen-equivalent values
What is the requirement for peripheral vision?
at least 70deg in the horizontal meridian in each eye
When peripheral vision test results are inconclusive, you should…
Have the evaluation performed by a specialist with equipment capable of precise measurements
What is the color vision requirement?
The ability to recognize and distinguish among red, amber, and green, the standard colors of traffic control signals and devices.
What is considered monocular vision?
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.
Why is monocular vision disqualifying?
In low illumination or glare, it can cause deficiencies in contrast recognition and depth perception compared to binocular vision.
Monocular vision is disqualifying
The driver with monocular vision who is otherwise qualified may…
Apply for a Federal Vision Exemption
How should a driver with an already valid federal vision exemption be examined?
At ANNUAL recertification, driver should present a valid vision exemption and a copy of the specialist eye examination report BEFORE receiving the medical examiner’s certificate.
Qualified drivers with a valid federal vision exemption may be qualified for …
Up to one year
When applying for a federal medical exemption, the driver should…
Include a copy of the medical examiner’s report form and the medical examiner’s certificate with the application.
How should the medical examiner’s certificate be completed if driver is applying to the federal vision exemption program?
Certify the driver for up to 1 year, and mark the “accompanied by” exemption checkbox and write “vision” to identify the type of exemption.
Also provide the driver with a copy of the medical examination report.
If a driver is using ophthalmic preparations to treat a condition, what must the medical examiner determine?
If the treatment is having the desired effect of preserving vision that meets the qualification requirements without any visual and/or systemic side effects that interfere with safe driving.
Slow, progressive opacification of the crystalline lens of the eye that distorts the optical passage of light to the retina resulting in diminished visual acuity
Cataracts
Can be accelerated by conditions such as injury, exposure to radiation, gout, certain meds (steroids), and DM
____ may be an early symptoms of cataracts
Glare, particularly during night driving in the face of oncoming headlights
What is the treatment for cataracts?
Surgical removal and placement of an intraocular lens
Glaucoma is caused by
Abnormal regulation of intraocular pressure, resulting in gradual progressive atrophy of optic nerve cells
Can vision loss caused by glaucoma be restored?
No
Therapeutic goal is to lower intraocular pressure to a level that preserves existing neuronal cells and prevents further loss of the peripheral visual field deficit.
Leading cause of untreatable legal blindness in the US
Macular Degeneration
Vision loss from MD is typically…
Interference with detailed, central vision
Peripheral vision is generally spared
The use of ____ lens are not acceptable for commercial driving
Telescopic lenses
Used for MD, they redirect unaffected peripheral vision to compensate for lost central acuity, resulting in reduced peripheral vision
Noninflammatory damage to the retina of the eye, most commonly caused by DM.
Retinopathy
Common after 5-7 years with DM
How to prevent retinopathy
Strict control of blood glucose and medical control of comorbid diseases (eg HTN, renal disease, cardiac disease)
Medical guidelines for the driver with DM
Annual medical examination
Annual ophthalmologist or optometrist eye evaluation
Disqualification for a diagnosis of unstable proliferative retinopathy.
______ retinopathy is characterized by rapid onset of blindness caused by retinal degeneration, usually of photoreceptors
Carcinoma-associated retinopathy
______ retinopathy can be a complication of sickle cell disease and sickle cell-thalassemia disease
Proliferative retinopathy
