retino-, retin- +
(Latin: innermost tunic of the eye; from ret[e], "net" plus -ina, "like")
The choroid is the middle layer of the vertebrate eye, between the retina and the sclera (tough white outer coat of the eyeball).
The ciliary body refers to the tissue that includes the group of muscles that act on the eye lens to produce accommodation and the arterial circle of the iris.
The inner ciliary epithelium (covering of internal and external surfaces) is continuous with the pigmented retinal epithelium, the outer ciliary epithelium secretes the aqueous humor.
An electrode placed on a plastic contact lens is used to pick up voltage from the surface of the eyeball.2. A test in which the electrical potentials generated by the retina of the eye are measured when the retina is stimulated by light.
The instrument used to do such electroretinography is known as an electroretinograph and the resultant recording is called an electroretinogram.
In an ERG, an electrode is placed on the cornea at the front of the eye. The electrode measures the electrical response of the rods and cones, and the visual cells in the retina at the back of the eye.
An ERG (electroretinograph) may be useful in the evaluation of hereditary and acquired disorders of the retina.
A normal ERG shows the appropriate responses with increased light intensity. An abnormal ERG is found in conditions; such as, arteriosclerosis of the retina, detachment of the retina, and temporal arteritis with eye involvement.
2. The delicate multilayered light-sensitive membrane lining the inner posterior chamber of the eyeball containing the rods and cones and connected by the optic nerve to the brain.
The sensory membrane that lines most of the large posterior chamber of the vertebrate eye, or retina, is composed of several layers including photoreceptor cells, and functions as the immediate instrument of vision by receiving the image formed by the lens and converting it into chemical and nervous signals which reach the brain by way of the optic nerve.