Search results
Results from the WOW.Com Content Network
Cyclotropia cannot be corrected with prism spectacles in the way other eye position disorders are corrected. [12] (Nonetheless two Dove prisms can be employed to rotate the visual field in experimental settings.) For cyclodeviations above 5 degrees, surgery has normally been recommended. [13]
The strength of the prism is increased until the streak of the light passes through the centre of the prism, as the strength of the prism indicates the amount of deviation present. The Maddox rod is a handheld instrument composed of red parallel plano convex cylinder lens , which refracts light rays so that a point source of light is seen as a ...
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Donate; Help; Learn to edit; Community portal; Recent changes; Upload file
AE Prism viewfinder FE401 [28] No 0.79x Silicon Photo Diode: EV-1.15 to EV 19 8 sec. 1/1000 25-6400 (set on film back) LED shutter speed Camera Yes +/- 3 stops Camera No Smooth shape from 645 Pro and Pro TL, two dials on top (metering mode and exposure compensation) AE Prism viewfinder FK402 [29] No 0.79x Silicon Photo Diode: EV-1.15 to EV 19 8 ...
Fixation disparity is a tendency of the eyes to drift in the direction of the heterophoria.While the heterophoria refers to a fusion-free vergence state, the fixation disparity refers to a small misalignment of the visual axes when both eyes are open in an observer with normal fusion and binocular vision. [1]
In some lenses, the curved surfaces are replaced with flat surfaces, with a different angle in each section. Such a lens can be regarded as an array of prisms arranged in a circular fashion with steeper prisms on the edges and a flat or slightly convex center. In the first (and largest) Fresnel lenses, each section was actually a separate prism.
Prism adaptation is a sensory-motor adaptation that occurs after the visual field has been artificially shifted laterally or vertically. It was first introduced by Hermann von Helmholtz in late 19th-century Germany as supportive evidence for his perceptual learning theory (Helmholtz, 1909/1962). [1]
A fisheye lens is an ultra wide-angle lens that produces strong visual distortion intended to create a wide panoramic or hemispherical image. [4] [5]: 145 Fisheye lenses achieve extremely wide angles of view, well beyond any rectilinear lens.