Search results
Results from the WOW.Com Content Network
The same water in a smaller bucket looks only slightly cyan, [1] and observing the water at close range makes it appear colorless to the naked eye. The intrinsic color of liquid water may be demonstrated by looking at a white light source through a long pipe that is filled with purified water and closed at both ends with a transparent window.
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
The vertebrate eye is usually either optimised for underwater vision or air vision, as is the case in the human eye. The visual acuity of the air-optimised eye is severely adversely affected by the difference in refractive index between air and water when immersed in direct contact.
The pupil of the human eye can range in size from 2 mm to over 8 mm to adapt to the environment. The human eye can detect a luminance from 10 −6 cd/m 2, or one millionth (0.000001) of a candela per square meter to 10 8 cd/m 2 or one hundred million (100,000,000) candelas per square meter.
The word turquoise dates to the 17th century and is derived from the Old French turquois meaning "Turkish" because the mineral was first brought to Europe through the Ottoman Empire. [ 6 ] [ 3 ] [ 4 ] [ 7 ] [ 8 ] However, according to Etymonline , the word dates to the 14th century with the form turkeis , meaning "Turkish", which was replaced ...
In animal and human hosts, infestation by Thelazia may be asymptomatic, though it frequently causes watery eyes , conjunctivitis, corneal opacity, or corneal ulcers (ulcerative keratitis). [1] Infested humans have also reported "foreign body sensation" – the feeling that something is in the eye.
Monochromacy (from Greek mono, meaning "one" and chromo, meaning "color") is the ability of organisms to perceive only light intensity without respect to spectral composition. Organisms with monochromacy lack color vision and can only see in shades of grey ranging from black to white. Organisms with monochromacy are called monochromats.
It is usually caused by allergies or viral infections, often inciting excessive eye rubbing. Chemosis is also included in the Chandler Classification system of orbital infections. If chemosis has occurred due to excessive rubbing of the eye, the first aid to be given is a cold water wash for eyes. [citation needed] Other causes of chemosis include: