Color blindnessColor blindness or color vision deficiency (CVD) is the decreased ability to see color or differences in color. It can impair tasks such as selecting ripe fruit, choosing clothing, and reading traffic lights. Color blindness may make some academic activities more difficult. However, issues are generally minor, and people with colorblindness automatically develop adaptations and coping mechanisms. People with total color blindness (achromatopsia) may also be uncomfortable in bright environments and have decreased visual acuity.
Astronomical filterAn astronomical filter is a telescope accessory consisting of an optical filter used by amateur astronomers to simply improve the details and contrast of celestial objects, either for viewing or for photography. Research astronomers, on the other hand, use various band-pass filters for photometry on telescopes, in order to obtain measurements which reveal objects' astrophysical properties, such as stellar classification and placement of a celestial body on its Wien curve.
BlueBlue is one of the three primary colours in the RYB colour model (traditional colour theory), as well as in the RGB (additive) colour model. It lies between violet and cyan on the spectrum of visible light. The term blue generally describes colors perceived by humans observing light with a dominant wavelength between approximately 450 and 495 nanometres. Most blues contain a slight mixture of other colours; azure contains some green, while ultramarine contains some violet.
Blurred visionBlurred vision is an ocular symptom where vision becomes less precise and there is added difficulty to resolve fine details. Temporary blurred vision may involve dry eyes, eye infections, alcohol poisoning, hypoglycemia, or low blood pressure. Other medical conditions may include refractive errors such as myopia, high hypermetropia, and astigmatism, amblyopia, presbyopia, pseudomyopia, diabetes, cataract, pernicious anemia, vitamin B12 deficiency, thiamine deficiency, glaucoma, retinopathy, hypervitaminosis A, migraine, sjögren's syndrome, floater, macular degeneration, and can be a sign of stroke or brain tumor.
