Guide for Aviation Medical Examiners
Application Process for Medical Certification - Examination Equipment and Techniques
Item 50. Distant Vision
Visual Acuity Standards
- As listed below or better;
- Each eye separately;
- Snellen equivalent; and
- With or without correction. If correction is used, it should be noted and the correct limitation applied.
Note: If correction is required to meet standards, only corrected visual acuity needs to be tested and recorded. Remember to apply the vision limitation to the medical certificate.
|Distant Vision||First or Second Class||Third Class|
- Snellen 20-foot eye chart may be used as follows:
- The Snellen chart should be illuminated by a 100-watt incandescent lamp placed 4 feet in front of and slightly above the chart (approximately 1600 lumens).
- The chart or screen should be placed 20 feet from the applicant's eyes and the 20/20 line should be placed 5 feet 4 inches above the floor.
- A metal, opaque plastic, or cardboard occluder should be used to cover the eye not being examined.
- The examining room should be darkened with the exception of the illuminated chart or screen.
- If the applicant wears corrective lenses, only the corrected acuity needs to be checked and recorded. If the applicant wears contact lenses, see the recommendations in Chapter 3, Items 31-34. Eye - Contact Lenses.
- Common errors:
- Failure to shield the applicant's eyes from extraneous light.
- Permitting the applicant to view the chart with both eyes.
- Failure to observe the applicant's face to detect squinting.
- Incorrect sizing of projected chart letters for a 20-foot distance.
- Failure to focus the projector sharply.
- Failure to obtain the corrected acuity when the applicant wears glasses.
- Acceptable Substitutes for Distant Vision Testing: Any commercial available visual acuities and heterphoria testing devices.
- Directions furnished by the manufacturer or distributor should be followed when using substitute devices for the above testing.
- Each eye will be tested separately, and both eyes together.
Last updated: Tuesday, December 27, 2022