Search results
Results from the WOW.Com Content Network
Light sensitivity or photosensitivity refers to a notable or increased reactivity to light. Apart from vision , human beings have many physiological and psychological responses to light. In rare individuals an atypical response may result in serious discomfort, disease, or injury.
Photophobia is a medical symptom of abnormal intolerance to visual perception of light. [1] As a medical symptom, photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of actual physical sensitivity of the eyes, [2] though the term is sometimes additionally applied to abnormal or irrational fear of light, such as ...
Photosensitivity is the amount to which an object reacts upon receiving photons, especially visible light.In medicine, the term is principally used for abnormal reactions of the skin, and two types are distinguished, photoallergy and phototoxicity.
uncontrollable squinting/closing of eyes; light sensitivity (photophobia) squinting/eyes closing during speech; uncontrollable eyes closing shut (rare instances completely causing blindness) In addition, in some patients, the dystonic spasms may sometimes be provoked by certain activities, such as talking, chewing, or biting.
The retina lines the inside of the eye. It is light-sensitive and communicates visual messages to the brain. If the retina detaches, it moves and shifts from its normal position. This can cause photopsia, but can also cause permanent vision loss. Medical attention is needed to prevent vision loss.
Heliophobia refers to light sensitivity: In psychology, heliophobia is the morbid fear of sunlight; In medicine it can refer to: Hemeralopia, day blindness, inability to see clearly in bright light; Photophobia, an excessive sensitivity of the eyes to sunlight. Notable causes include:
The term comes from the Greek skotos, meaning 'darkness', and -opia, meaning 'a condition of sight'. [2] In the human eye, cone cells are nonfunctional in low visible light. Scotopic vision is produced exclusively through rod cells, which are most sensitive to wavelengths of around 498 nm [3] and are insensitive to wavelengths longer than about ...
For the blue-green region (500 nm), 50% of the light reaches the image point of the retina. [2] Adaptation is much faster under photopic vision; it can occur in 5 minutes for photopic vision but it can take 30 minutes to transition from photopic to scotopic. [2] Most older adult humans lose photopic spatial contrast sensitivity.