Defect of vision due to the radius of curvature of the optics of the eye--especially the cornea--being unequal at different orientations around the visual axis. Lines or bars at different orintations are not all simultaneously in focus, and there can be distortions for some orientations.

(c) Oxford University Press

Richard Gregory, Oxford Companion to the Mind.

Aberration - Barrel
Aberration - Chromatic
Aberration - Coma
Aberration - Curvature of Field
Aberration - Pincushion
Aberration - Spherical

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