ABSTRACT
Vision is most important sense in aviation. Small refractive errors should be corrected for flying. Abnormal colour vision limits employment in pilot role. Contact lenses are most popular refractive correction for flying. Corneal refractive surgery is allowed for aircrew. Vision is most important sense needed for flying. Vision is only sensory means for orientation in space. Brain processes visual information by: focal system and ambient system. Visual acuity commonly refers to clarity of vision. Refractive error means that focusing structures of eye do not focus light correctly, resulting in a blurred image. Main types of refractive errors are: myopia, hypermetropia, astigmatism and presbyopia. Ocular imbalance can result in a misalignment of eyes known as squint or strabismus. Tropias can be diagnosed using the cover/uncover test. Distortions in canopy or windscreen can give false perception. Multiple reflections, dirt or oil staining may reduce visual performance.
