VISUAL ACUITY UNDER WATER WITHOUT A FACE MASK

Abstract

Visual acuity was measured under water for subjects without face masks and was compared with their acuity in air. The loss of acuity was around 90 percent for the entire group, but there were marked differences for the various sub-groups. Emmetropes suffered the greatest loss in the water; they required targets more than 20 times as big as those they could see in air. Myopes suffered the least loss; they required an increase in target-size by a factor of only seven. There was no correlation between emmetropic acuity in air and in water. Acuity was also measured at various luminances in air while the subjects wore negative lenses of various powers to induce the same type of out- of-focus vision found under water. High and low contrast targets were used. Calculations were made of the approximate target sizes which can be seen under water at various light levels and at the two levels of contrast.

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Document Details

Document Type
Technical Report
Publication Date
May 19, 1969
Accession Number
AD0693472

Entities

People

  • Joann S. Kinney
  • S. M. Luria

Organizations

  • Naval Submarine Medical Research Laboratory

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Abstracts
  • Biomedical Research
  • Classification
  • Contrast
  • Eye Diseases
  • Luminance
  • Navy
  • Optical Phenomena
  • Optical Properties
  • Orientation (Direction)
  • Refraction
  • Security
  • Submarine Bases
  • Submarines
  • Sunlight
  • Targets
  • Visual Acuity

Readers

  • Circadian Sleep-Wake Regulation and Chronobiology
  • Mathematics or Statistics