Optical Axis and Visual Axis
The optical axis is the centre of a lens where light travels through and is not bent. The visual axis is where light travels through the eye to the retina and is essentially understood to not be bent.
Sometimes glasses are given with the optical axis shifted away from the visual axis. This creates a prismatic effect. Prisms can be used to diagnose and treat binocular vision and other orthoptics problems which cause diplopia such as:
- Positive and negative fusion problems
- Positive relative accommodation and negative relative accommodation problems
Read more about this topic: Eyeglass Prescription
Famous quotes containing the words optical, axis and/or visual:
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—Alexander Herzen (1812–1870)
“He is the essence that inquires.
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And his mind is the sky,
Than all it holds more deep, more high.”
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“The visual is sorely undervalued in modern scholarship. Art history has attained only a fraction of the conceptual sophistication of literary criticism.... Drunk with self-love, criticism has hugely overestimated the centrality of language to western culture. It has failed to see the electrifying sign language of images.”
—Camille Paglia (b. 1947)