The Choroid.
choroid
the Iris
The pigmented tunic you are referring to is the choroid, which contains melanin that absorbs excess light and prevents it from scattering within the eye. This helps to improve visual acuity and reduce glare.
choroid :)
The consensual light reflex is a normal eye response where shining a light into one eye causes both pupils to constrict. This reflex helps maintain proper visual sensitivity and protects the eye from bright light by regulating the amount of light entering the eye.
choroid - a highly vascular membrane in the eye between the retina and the sclera; a dark pigmentation minimizes the scattering of light inside the eye.(http://www.thefreedictionary.com/choroid)
Light is invisible to the human eye because our eyes can only detect a small range of wavelengths within the electromagnetic spectrum, and light falls within a range that is visible to us.
paglo
The Choroid is black because its heavily pigmented because of an excess of melanin. Also, the dark colour of the choroid prevents internal reflection in the eye, so to ensure the image received is not blurred.
The tapetum lucidum (reflective material) reflects light back into the retina. This allows the animal to see at night. (Although this allows for better night vision than that of humans, it distorts the clarity because the light is reflected so much.) The tapetum lucidum is also responsible for the "glowing" eyes of animals, such as cats, when a small amount of light reflects off the tapetum lucidum in an otherwise dark room.
False.
Infared is a type of light that is not visible to the human eye.