FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute

Report No: DOT/FAA/AM-13/16

Title and Subtitle: Evaluation of the Stereo Optical OPTEC 5000 for Aeromedical Color Vision Screening

Report Date: August 2013

Authors: Milburn NJ, Roberts CA, Perry DL

Abstract: Screening tests are valued for their ability to detect the presence (test sensitivity) and the absence (test specificity) of a disease or a specific condition such as color vision deficiencies (CVDs). From an aviation safety standpoint, it is important to identify those with CVDs because of their potential for accidents if they misinterpret vital color-coded information; whereas, failing an airman with normal color vision has other consequences to the Federal Aviation Administration (FAA) such as the expense of secondary screening. If a screening test has low specificity, it can have a high false positive rate-meaning that individuals are falsely noted as having the condition being screened. So, from the airman's standpoint, especially if the airman has normal color vision (NCV), specificity is very important. The FAA has a color vision standard for airmen and air traffic controllers because of the occupations' high reliance on color-coded information.

Stereo Optical Company, Inc. requested a review of their model 5000 multifunction screener for aeromedical use, and the FAA found that instrument failed 50% of those with NCV. The manufacturer made some modifications and requested a re-evaluation. The validity of the original and modified versions of the OPTEC 5000 (called V1 and V2, respectively in this paper) was examined in two experiments.

Experiment 1 involved 29 NCV and 31 CVD subjects that were administered the OPTEC 2000 and the V1. Experiment 2 examined the validity of the original and modified instruments by comparing test outcome on both versions to a diagnostic test using 50 NCV and 51 CVD subjects.

In Experiment 1, the V1 failed 41.3% of the NCV participants. In Experiment 2, V1 failed 28%, and V2 failed 32% of the NCV subjects. V1 passed 16% of the subjects diagnosed with CVDs and V2 erroneously passed 12%. It is possible that the light-emitting diode strip, used in the OPTEC 5000, altered the color perception of the pseudo-isochromatic test plates and that substituting that light source for one with better color rendering could restore the test's sensitivity and specificity rates. The specificity of the OPTEC 5000, in its original and modified states, are unacceptably low; and neither should be used for aeromedical color vision screening because of their low agreement with a diagnostic test (K(101)=.564 and .563, respectively).

Key Words: Color Vision Deficiency, Color Vision, Color Vision Screening Tests, OPTEC 5000

No. of Pages: 18