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The Krimsky test is essentially the Hirschberg test, but with prisms employed to quantitate deviation of ocular misalignment by determining how much prism is required to centre the reflex. [2] The Krimsky test is advisably used for patients with tropias, but not with phorias.
A prism spectrometer is an optical spectrometer which uses a dispersive prism as its dispersive element. The prism refracts light into its different colors ( wavelengths ). The dispersion occurs because the angle of refraction is dependent on the refractive index of the prism's material, which in turn is slightly dependent on the wavelength of ...
A familiar dispersive prism. An optical prism is a transparent optical element with flat, polished surfaces that are designed to refract light. At least one surface must be angled — elements with two parallel surfaces are not prisms. The most familiar type of optical prism is the triangular prism, which has a triangular base and rectangular ...
The prism cover test (PCT) is an objective measurement and the gold standard in measuring strabismus, i.e. ocular misalignment, or a deviation of the eye. [1] It is used by ophthalmologists, orthoptists, and optometrists in order to measure the vertical and horizontal deviation and includes both manifest and latent components. [1]
The second prism should have an index of refraction higher than that of the liquid, so that light only enters the prism at angles smaller than the critical angle for total reflection. This angle can then be measured either by looking through a telescope, [clarification needed] or with a digital photodetector placed in the focal plane of a lens.
A ray trace through a prism with apex angle α. Regions 0, 1, and 2 have indices of refraction, , and , and primed angles ′ indicate the ray's angle after refraction.. Ray angle deviation and dispersion through a prism can be determined by tracing a sample ray through the element and using Snell's law at each interface.
When the prism is placed in front of the non-deviating eye, the eye under the prism will move in and the fellow eye move out in the same way discussed above due to Herring's law. However similarly to the response given by a patient with central suppression, the fellow eye will not make a fusional convergence movement back in as the image ...
Refraction error: A correctly-focused eye (top), and two showing refractive error: In the middle image, the light is focused too far forward; in the bottom image, the focal point is behind the eye. Specialty: Ophthalmology, optometry: Symptoms: Blurry vision, double vision, headaches, eye strain: Complications: Blindness, amblyopia [1] [2] Types