The requirements for the Depth Perception Test is most difficult to explain as even complete failure on this test, unless it is supported by other evidence, is not necessarily indicative of poor, insufficient or inadequate depth perception.
Fueling confusion and angst many have pertinent to this test is the Air Force’s historical utilization of the depth perception test to screen and evaluate undergraduate pilot candidates for type of aircraft (fighter, bomber, cargo-transport, helicopter) they were most suitable to operate. That failure of the depth perception test often failed to proceed to further medical evaluation to include failure reviewed by the Aeromedical Consultation Service (ACS) resulted in many undergraduate pilot candidates getting false failures being eliminated from pilot training and qualification.
Currently confusion is sustained by lack of clearly identifying what Flying and Special Operation Duty AFSCs’ require individuals to meet or not meet some sort of depth perception requirement combined with a waiver for the failure cause to include severity of failure with best corrected visual acuity to be unlikely for untrained personnel.
The most common cause of an acquired depth perception defect is uncorrected refractive error.
Failure of depth perception with best corrected visual acuity is disqualifying, but may be considered for waiver.
The PULHES factor of ‘1’ for eyes is “minimum vision of 20/200 correctable to 20/20 in each eye”. This generally correlates to presence of Distance Perception Abilities impairment of “Very Poor for nonmoving objects”. However, vision impairment often involves one eye being worse than the other. In such circumstances there is potential for the poor quality image from the bad eye is superimposed by the brain on the sharp, clear image seen by the good eye. In these instances, the sharp vision is degraded by the blurred vision of the bad eye. The example emphasis is a person is seeing clearly with two good eyes (normal stereoscopic vision) are more able to quickly and accurately judge distances. People who see with just one eye lack this tool. People having normal vision in one eye and reduced- or low- vision in the other eye, either lack this tool or have it in reduced form. This is a potential cause for why failure of depth perception with best corrected acuity may prevent a waiver being approved for entry classification (job Placement) in some AFSCs and not others.
It should be noted (reference Army Regulation 40-501) the minimum uncorrected vision worse than 20/70 in either eye is disqualifying for free fall parachute training (high altitude low opening (HALO), marine diving (Special Forces and Ranger combat diving) and other marine diving. There is a judging distance perception concern connected to this disqualification requirement.
There are many other possible or potential medical disqualification casuals for Depth Perception Test failure. Some individuals are unable to accurately perceive depth secondary to developmental abnormalities of the neuro-retinal pathway. Examples being strabismic amblyopia (a misalignment of the optical axis), anisometropic amblyopia (due to retinal image size disparity or clarity differences secondary to differential refraction between the two eyes) and deprivation amblyopia (from opacities or blockage of the optical media such as cataract, ptosis or uniocular retinal disorder). Some are acquired with the development of cataracts or worsening of a diabetic affliction. Regardless the nature of performing duties of the AFSC under harsh conditions at the extremes of human physical capabilities still influences the allowable waiverable base line.