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The image of the pupil as seen from outside the eye is the entrance pupil, which does not exactly correspond to the location and size of the physical pupil because it is magnified by the cornea. On the inner edge lies a prominent structure, the collarette , marking the junction of the embryonic pupillary membrane covering the embryonic pupil.
The apparent location of the anatomical pupil of a human eye (black circle) is the eye's entrance pupil location. The outside world appears to be seen from the point at the center of the entrance pupil. The anatomical pupil itself is slightly different from the entrance pupil because the image is magnified by the cornea.
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 exit pupil is an image of the aperture made by the optics following it; divergent rays from each point in the aperture plane come together again in the exit pupil. To use an optical instrument, the entrance pupil of the viewer's eye (the image of the anatomical pupil as seen through the cornea ) must be aligned with and be of similar size ...
An image of a house fly compound eye surface by using scanning electron microscope Anatomy of the compound eye of an insect Arthropods such as this blue bottle fly have compound eyes. A compound eye may consist of thousands of individual photoreceptor units or ommatidia (ommatidium, singular). The image perceived is a combination of inputs from ...
The term gaze is frequently used in physiology to describe coordinated motion of the eyes and neck. The lateral gaze is controlled by the paramedian pontine reticular formation (PPRF). [ 1 ] The vertical gaze is controlled by the rostral interstitial nucleus of medial longitudinal fasciculus and the interstitial nucleus of Cajal .
The iris (pl.: irides or irises) is a thin, annular structure in the eye in most mammals and birds that is responsible for controlling the diameter and size of the pupil, and thus the amount of light reaching the retina. In optical terms, the pupil is the eye's aperture, while the iris is the diaphragm. Eye color is defined by the iris.
More specifically, the entrance pupil as the front side image of the aperture and focal length of an optical system determine the cone angle of a bundle of rays that comes to a focus in the image plane. An optical system typically has many openings or structures that limit ray bundles (ray bundles are also known as pencils of light).