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 Post subject: Stiles-Crawford does not apply to night vision
PostPosted: Wed Oct 24, 2007 2:51 pm 
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Leo J. Maguire, MD, Mayo Clinic Ophthalmologist and former FDA consultant:

Quote:
The problems with pupil-related aberration are further magnified by the reality that the Stiles-Crawford effect is negated in night vision.



The retina is a complex tissue in the back of the eye that contains specialized photoreceptor cells called rods and cones. The photoreceptors connect to a network of nerve cells for the local processing of visual information. This information is sent to the brain for decoding into a visual image.

Cones work in bright light. Cones are less numerous in the periphery of the retina.

Rods are inactive in bright light. Rods control night vision.

Stiles-Crawford effect is a property of the cone photoreceptors of the retina. Because cones are less numerous in the periphery of the retina, light passing near the edge of the pupil in bright light is less efficient at evoking sensation than light passing through the center of the pupil. This is not true of night vision when the rods, not the cones, are dominant.

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