Search results
Results from the WOW.Com Content Network
Closed-eye hallucination. Closed-eye hallucinations and closed-eye visualizations ( CEV) are hallucinations that occur when one's eyes are closed or when one is in a darkened room. They should not be confused with phosphenes, perceived light and shapes when pressure is applied to the eye's retina, or some other non-visual external cause ...
Cyanopsia. Cyanopsia is a medical term for seeing everything tinted with blue. It is also referred to as blue vision. Cyanopsia often occurs for a few days, weeks, or months after removal of a cataract from the eye. Cyanopsia also sometimes occurs as a side effect of taking sildenafil, tadalafil, or vardenafil. [1]
Color vision. Colorless, green, and red photographic filters as imaged by camera. Color vision, a feature of visual perception, is an ability to perceive differences between light composed of different frequencies independently of light intensity. Color perception is a part of the larger visual system and is mediated by a complex process ...
Synesthesia. A person with synesthesia may associate certain letters and numbers with certain colors. Most synesthetes see characters just as others do (in whichever color actually displayed) but they may simultaneously perceive colors as associated with or evoked by each one. Synesthesia ( American English) or synaesthesia ( British English ...
An afterimage is an image that continues to appear in the eyes after a period of exposure to the original image. An afterimage may be a normal phenomenon (physiological afterimage) or may be pathological ( palinopsia ). Illusory palinopsia may be a pathological exaggeration of physiological afterimages. Afterimages occur because photochemical ...
The visible spectrum is the band of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light (or simply light). The optical spectrum is sometimes considered to be the same as the visible spectrum, but some authors define the term more broadly, to include the ...
The irises of human eyes exhibit a wide spectrum of colours. Eye color is a polygenic phenotypic trait determined by two factors: the pigmentation of the eye 's iris [1] [2] and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris. [3] : 9. In humans, the pigmentation of the iris varies from light ...
Cosmic ray visual phenomena, or light flashes ( LF ), also known as Astronaut's Eye, are spontaneous flashes of light visually perceived by some astronauts outside the magnetosphere of the Earth, such as during the Apollo program. While LF may be the result of actual photons of visible light being sensed by the retina, [1] the LF discussed here ...