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Red reflex. The red reflex (also called the fundal reflex) refers to the reddish-orange reflection of light from the back of the eye, or fundus, observed when using an ophthalmoscope or retinoscope. It is important to note that the red reflex may be absent or poorly visible in people with dark eyes, and may even appear yellow in Asians or green ...
Red-eye effect seen on a teenager. The red-eye effect in photography is the common appearance of red pupils in color photographs of the eyes of humans and several other animals. It occurs when using a photographic flash that is very close to the camera lens (as with most compact cameras) in ambient low light.
Ophthalmology, pediatrics. Leukocoria (also white pupillary reflex) is an abnormal white reflection from the retina of the eye. Leukocoria resembles eyeshine, but leukocoria can also occur in animals that lack eyeshine because their retina lacks a tapetum lucidum . Leukocoria is a medical sign for a number of conditions, including Coats disease ...
The tapetum lucidum ( Latin for 'bright tapestry, coverlet'; / təˈpiːtəm ˈluːsɪdəm / tə-PEE-təm LOO-sih-dəm; pl.: tapeta lucida) [ 1] is a layer of tissue in the eye of many vertebrates and some other animals. Lying immediately behind the retina, it is a retroreflector. It reflects visible light back through the retina, increasing ...
The choroid, also known as the choroidea or choroid coat, is a part of the uvea, the vascular layer of the eye. It contains connective tissues, and lies between the retina and the sclera. The human choroid is thickest at the far extreme rear of the eye (at 0.2 mm), while in the outlying areas it narrows to 0.1 mm. [ 1 ] The choroid provides ...
Retinoblastoma (Rb) is a rare form of cancer that rapidly develops from the immature cells of a retina, [ 2] the light-detecting tissue of the eye. [ 3] It is the most common primary malignant intraocular cancer in children, especially those under 3 years old. [ 4][ 5] Though most children in high income countries survive this cancer, [ 2] they ...
Color vision. Colorless, green, and red photographic filters as imaged by camera. Color vision, a feature of visual perception, is an ability to perceive differences between light composed of different frequencies independently of light intensity. Color perception is a part of the larger visual system and is mediated by a complex process ...
One early warning sign of Coats' disease is yellow-eye in flash photography. Just as the red-eye effect is caused by a reflection off blood vessels in the back of a normal eye, an eye affected by Coats' will glow yellow in photographs as light reflects off cholesterol deposits. Children with yellow-eye in photographs are typically advised to ...