Glare (vision)
Glare (vision)
Glare (/ɡlɛər/) is a visual sensation caused by excessive and uncontrolled brightness. It can be disabling or simply uncomfortable. It is subjective and sensitivity to glare can vary widely.
Etymology
The term "glare" originates from the Middle English word 'glaren' or 'gleren' (to shine, gleam). It is possibly related to the Old English 'glær' which means 'amber'.
Types of Glare
There are three types of glare:
- Disability Glare: This type of glare impairs the vision of objects without necessarily causing discomfort. This could occur, for example, when driving westward at sunset.
- Discomfort Glare: This type of glare produces discomfort. It does not necessarily impair the vision of objects.
- Dazzle: This type of glare is caused by extremely bright lights, causing a momentary blindness.
Causes
Glare can be generally caused by a significant contrast in light intensity in the visual field. Some specific causes include:
- Direct Sunlight: Direct sunlight can cause significant glare, especially when it is low on the horizon.
- Artificial Light: Artificial light can cause glare if it is too bright or if it is coming from a particular direction.
- Reflections: Glare can be caused by light reflecting off a surface like a white paper, a white wall, or a wet road.
Effects
Glare can have several effects on the vision:
- Reduced Contrast: Glare can reduce the contrast of the visual image, making it harder to see details.
- Visual Discomfort: Glare can cause visual discomfort, leading to squinting, eye fatigue, and headaches.
- Impaired Visual Performance: Glare can impair visual performance, making it harder to perform tasks that require good vision.
Prevention and Control
There are several ways to prevent or control glare:
- Sunglasses: Sunglasses can help to reduce glare from the sun.
- Window Shades: Window shades can be used to control glare from windows.
- Anti-Reflective Coating: Anti-reflective coating on glasses can help to reduce glare.
See Also
External links
- Medical encyclopedia article on Glare (vision)
- Wikipedia's article - Glare (vision)
This WikiMD dictionary article is a stub. You can help make it a full article.
Languages: - East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
Urdu,
বাংলা,
తెలుగు,
தமிழ்,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
European
español,
Deutsch,
français,
русский,
português do Brasil,
Italian,
polski