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Nov 27, 2009
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Encyclopediavision

Defects of Vision

Defects of vision include astigmatism, color blindness, farsightedness, and nearsightedness. The absence of rods causes a condition known as night blindness; an absence of cones constitutes legal blindness.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2007, Columbia University Press. All rights reserved.

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