Search results
Results from the WOW.Com Content Network
The extraneous pupil is c. 2.5mm away from the principal pupil. In cases of true polycoria there is an intact sphincter muscle, which contracts and dilates the pupils. [5] In an eye without polycoria, the sphincter muscle is a part of the iris that functions to constrict and dilate the pupil.
The pupil constricts when the iris sphincter muscle is stimulated and contracts In humans, it functions to constrict the pupil in bright light ( pupillary light reflex ) or during accommodation . [ citation needed ] In lower animals, the muscle cells themselves are photosensitive causing iris action without brain input.
It is a common problem experienced by people of all ages. Related eye symptoms and signs of irritation are discomfort, dryness, excess tearing, itchiness, grating, foreign body sensation, ocular fatigue, pain, soreness, redness, swollen eyelids, and tiredness, etc. These eye symptoms are reported with intensities from mild to severe.
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.
The eye is made up of the sclera, the iris, and the pupil, a black hole located at the center of the eye with the main function of allowing light to pass to the retina. Due to certain muscle spasms in the eye, the pupil can resemble a tadpole, which consists of a circular body, no arms or legs, and a tail.
Parinaud's syndrome is a cluster of abnormalities of eye movement and pupil dysfunction, characterized by: Paralysis of upwards gaze: Downward gaze is usually preserved. This vertical palsy is supranuclear, so doll's head maneuver should elevate the eyes, but eventually all upward gaze mechanisms fail. In the extreme form, conjugate down gaze ...
The iris is a thin circular structure in the eye which consists of two layers, on top is the stroma and underneath the pigmented epithelial cells. It separates the eye in the anterior and posterior chamber, is responsible for the eye's color, and its function is to regulate the size of the pupil.
accommodative iridoplegia- Noncontraction of pupils during accommodation. complete iridoplegia- Iris fails to respond to any stimulation. reflex iridoplegia- The absence of light reflex, with retention of accommodation reflex. Also called Argyll Robertson pupil.