defocus

(redirected from defocused)
Also found in: Dictionary, Encyclopedia.

defocus

(de-fo'kus) [L. de, away from, + focus, hearth]
The blurring of a visual image caused by spherical aberration, chromatic aberration, or diffraction. Also called optical defocus. Synonym: optical defocus

optical defocus

Defocus.

defocus

To put or go out of focus.
hyperopic defocus State of the eye in which the retinal image is focused behind the retina. It may occur when placing a negative lens in front of an emmetropic presbyopic eye; in an uncorrected presbyopic hyperope; in a high hyperope unable to overcome the ametropia by accommodating; or as an accommodative lag in an uncorrected or corrected myope, as well as in an emmetrope viewing a near object. See lag of accommodation; over-correction.
myopic defocus State of the eye in which the retinal image is focused in front of the retina. It may occur when placing a positive lens in front of an emmetropic eye; in an uncorrected or undercorrected myopic eye; or if there is a lead of accommodation, as is the case in some individuals viewing a distant object. See lead of accommodation; under-correction.
References in periodicals archive ?
Among his topics are optical transfer function, balanced aberrations and Zernike circle polynomials, a defocused system with annular pupils, line of sight of an aberrated system, and imaging through atmospheric turbulence.
2] laser at 10 ms, 2 W, and 30 m] defocused was used to cauterize the small peripheral vasculature.
Senior Bharatiya Janata Party leader Murli Manohar Joshi described the General Budget as highly defocused and the worst ever witnessed in his Parliamentary career so far.
that he almost offered to represent a friend in court, did shifts flipping burgers to essay a cook in Frankie and Johnny and defocused his eyes almost to the point of blindness to become a sightless former army colonel in Scent Of A Woman.
The company says that lasers with low order modes prove to have high intensity in the central point, and while they can be defocused, the intensity issue remains.
When defocused, it provides supplemental infrared illumination.
It also raises an alarm when a camera is redirected, masked, sprayed, or defocused.
Using a high-resolution transmission electron microscope at LBL, the scientists took 20 pictures of lithium cobalt oxide--each one deliberately defocused a little differently--with a nearly atomic resolution of 1.
Their eyes are still slightly defocused, showing internal worries that prevent them from really engaging with what's going on.