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:
“There is an optical illusion about every person we meet.”
—Ralph Waldo Emerson (1803–1882)
“He is the essence that inquires.
He is the axis of the star;
He is the sparkle of the spar;
He is the heart of every creature;
He is the meaning of each feature;
And his mind is the sky,
Than all it holds more deep, more high.”
—Ralph Waldo Emerson (1803–1882)
“The chess pieces are the block alphabet which shapes thoughts; and these thoughts, although making a visual design on the chess-board, express their beauty abstractly, like a poem.... I have come to the personal conclusion that while all artists are not chess players, all chess players are artists.”
—Marcel Duchamp (1887–1968)