defocus


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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 ?
Low light capabilities and background defocus are heightened by the high sensitivity and large sensor size.
The slider on the right side of the screen will allow users to adjust the level of defocus either horizontally or vertically.
A novel dual-focus (DF) soft contact lens, with a central correction zone and concentric treatment zones that simultaneously create myopic retinal defocus, has been shown to reduce the progression of both the myopic refractive error and the corresponding axial elongation of the eye.
Glasses or contact lenses that correct the defocus on the main visual axis can create a slight degree of farsightedness in the peripheral retina, David Troilo at SUNY College of Optometry in New York City explained.
07m, due to the rotation of the vortex, defocus before sharply focusing toward the vertical symmetry plane, where they cross their symmetric counterparts (not traced in the figure).
The Background Defocus mode, featured in the TX9 and WX5 models, provides artistic photos like those taken with a DSLR by making it easy to blur the image's background, putting the emphasis on your subject and creating a bokeh effect.
The eye responds to the imposed defocus by elongating to place the image on the retina, becoming functionally myopic.
1/8,000 sec not only to capture spur-of-the-moment action and fast moving subjects but also to allow users to use high-speed lens with an open aperture in outdoors to give impressive defocus.
Diplomats of Western countries in Skopje are concerned that some incident might emerge by the end of this week, to defocus the attention from the BDI scandals, which emerged with the publication of the "38th bomb", reports "lajmpress".
It also has a constant F4 maximum aperture, allowing photographers to achieve beautiful background defocus effects with a shallow depth of field at all focal lengths.
The new lens allows photographers to capture snapshots with beautiful defocus features produced by F1.
Defocus curve testing was employed to assess near vision abilities.