Search results
Results from the WOW.Com Content Network
Spectacles (glasses) to correct refractive errors of the eye; not invasive. Contact lenses. to correct refractive errors of the eye; a little invasive. Phoropter. used in refraction testing. Tonometers. used to determine the intraoccular pressure (IOP) - useful in glaucoma; video link for various types of tonometers.
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. It is used by ophthalmologists and orthoptists in order to measure the vertical and horizontal deviation and includes both manifest and latent components. [1]
Prism dioptres. Prism correction is commonly specified in prism dioptres, a unit of angular measurement that is loosely related to the dioptre. Prism dioptres are represented by the Greek symbol delta (Δ) in superscript. A prism of power 1 Δ would produce 1 unit of displacement for an object held 100 units from the prism. [2]
Iris recognition biometric systems apply mathematical pattern-recognition techniques to images of the irises of an individual's eyes.. Iris recognition is an automated method of biometric identification that uses mathematical pattern-recognition techniques on video images of one or both of the irises of an individual's eyes, whose complex patterns are unique, stable, and can be seen from some ...
Subjective Refraction is a technique to determine the combination of lenses that will provide the best corrected visual acuity (BCVA). [1] It is a clinical examination used by orthoptists, optometrists and ophthalmologists to determine a patient's need for refractive correction, in the form of glasses or contact lenses.
The Micro Four Thirds system cameras and lenses perform automatic distortion correction using correction parameters that are stored in each lens's firmware, and are applied automatically by the camera and raw converter software. The optics of most of these lenses feature substantially more distortion than their counterparts in systems that do ...
Tilt-lens photo of a model train. Note how the focus plane is along the train, and how the blurring of the background proceeds from left to right. Tilt–shift photography is the use of camera movements that change the orientation or position of the lens with respect to the film or image sensor on cameras .
Raw image format. A camera raw image file contains unprocessed or minimally processed data from the image sensor of either a digital camera, a motion picture film scanner, or other image scanner. [1] [2] Raw files are so named because they are not yet processed, and contain large amounts of potentially redundant data.
The Prentice position is an orientation of a prism, used in optics, optometry and ophthalmology. In this position, named after the optician Charles F. Prentice, the prism is oriented such that light enters it at an angle of 90° to the first surface, so that the beam does not refract at that surface. All the deviation caused by the prism takes ...
A Canon 7 mounted with a 50 mm lens capable of f / 0.95 A 35 mm lens set to f / 11, as indicated by the white dot above the f-stop scale on the aperture ring. This lens has an aperture range of f / 2 to f / 22. The word stop is sometimes confusing due to its multiple meanings. A stop can be a physical object: an opaque part of an optical system ...