Search results
Results From The WOW.Com Content Network
Accommodation is the process by which the vertebrate eye changes optical power to maintain a clear image or focus on an object as its distance varies. In this, distances vary for individuals from the far point —the maximum distance from the eye for which a clear image of an object can be seen, to the near point —the minimum distance for a ...
The patient is instructed to make a near target perfectly clear and their phoria is measured as the focusing demand on the eye is changed with lenses. To determine stimulus AC/A, the denominator refers to the value of the stimulus, whereas to determine response AC/A, the actual accommodation elicited is the denominator.
Light from a single point of a distant object and light from a single point of a near object being brought to a focus. The accommodation reflex (or accommodation-convergence reflex) is a reflex action of the eye, in response to focusing on a near object, then looking at a distant object (and vice versa), comprising coordinated changes in vergence, lens shape (accommodation) and pupil size.
A distant object is defined as an object located beyond 6 meters (20 feet) from the eye. [citation needed] When an object is located close to the eye, the rays of light from this object no longer approach the eye parallel to each other. Consequently, the eye must increase its refractive power to bring those rays of light together on the retina ...
His definitions include hyperfocal distance: Depth of Focus is a convenient, but not strictly accurate term, used to describe the amount of racking movement (forwards or backwards) which can be given to the screen without the image becoming sensibly blurred, i.e. without any blurring in the image exceeding 1/100 in., or in the case of negatives ...
Image distance in a spherical mirror + = () Subscripts 1 and 2 refer to initial and final optical media respectively. These ratios are sometimes also used, following simply from other definitions of refractive index, wave phase velocity, and the luminal speed equation:
Distance PD is the separation between the visual axes of the eyes in their primary position, as the subject fixates on an infinitely distant object. [2] Near PD is the separation between the visual axes of the eyes, at the plane of the spectacle lenses, as the subject fixates on a near object at the intended working distance. [3]
This is the only eye movement that is not conjugate, but instead adducts the eye. [7] Convergence is one of three processes an eye does to properly focus an image on the retina. In each eye, the visual axis will point towards the object of interest in order to focus it on the fovea. [ 8 ]