Ad
related to: kaleidoscope vision in eyesLensCrafters.com has been visited by 10K+ users in the past month
Search results
Results from the WOW.Com Content Network
Scintillating scotoma is a common visual aura that was first described by 19th-century physician Hubert Airy (1838–1903). Originating from the brain, it may precede a migraine headache, but can also occur acephalgically (without headache), also known as visual migraine or migraine aura. [4]
Persistence of vision is the optical illusion that occurs when the visual perception of an object does not cease for some time after the rays of light proceeding from it have ceased to enter the eye. [1] The illusion has also been described as "retinal persistence", [2] "persistence of impressions", [3] simply "persistence" and other variations.
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 ...
Aura. An aura is a perceptual disturbance experienced by some with epilepsy or migraine. An epileptic aura is actually a minor seizure. [1] Epileptic and migraine auras are due to the involvement of specific areas of the brain, which are those that determine the symptoms of the aura. Therefore, if the visual area is affected, the aura will ...
Retinal migraine is a retinal disease often accompanied by migraine headache and typically affects only one eye. It is caused by ischaemia or vascular spasm in or behind the affected eye. The terms "retinal migraine" and "ocular migraine" are often confused with "visual migraine", which is a far-more-common symptom of vision loss, resulting ...
Metamorphopsia (from Greek: μεταμορφοψία, metamorphopsia, 'seeing mutated shapes') is a type of distorted vision in which a grid of straight lines appears wavy and parts of the grid may appear blank. People can first notice they suffer with the condition when looking at mini-blinds in their home. For example, straight lines might be ...
Kaleidoscope. A toy kaleidoscope. A kaleidoscope ( / kəˈlaɪdəskoʊp /) is an optical instrument with two or more reflecting surfaces (or mirrors) tilted to each other at an angle, so that one or more (parts of) objects on one end of these mirrors are shown as a regular symmetrical pattern when viewed from the other end, due to repeated ...
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 between neurons that begins with differential stimulation of different types of ...
In the study of visual perception, scotopic vision (or scotopia) is the vision of the eye under low-light conditions. The term comes from the Greek skotos, meaning 'darkness', and -opia, meaning 'a condition of sight'. In the human eye, cone cells are nonfunctional in low visible light.
Entoptic phenomenon. Entoptic phenomena (from Ancient Greek ἐντός (entós) 'within', and ὀπτικός (optikós) 'visual') are visual effects whose source is within the human eye itself. (Occasionally, these are called entopic phenomena, which is probably a typographical mistake.) In Helmholtz 's words: "Under suitable conditions light ...