Search results
Results from the WOW.Com Content Network
Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurons send axons to neurons of the Edinger-Westphal nucleus whose visceromotor axons run along both the left and right oculomotor nerves .
The pupil diameter can vary greatly due to various factors (primarily the pupillary light reflex), from constriction to as small as 2 mm, to dilation larger than 8 mm in some individuals, though the maximal dilation also varies substantially by individual and decreases with age. The pupil gets wider in the dark and narrower in light.
Dilation and constriction of the pupil. Pupillary response is a physiological response that varies the size of the pupil, via the optic and oculomotor cranial nerve.. A constriction response (), [1] is the narrowing of the pupil, which may be caused by scleral buckles or drugs such as opiates/opioids or anti-hypertension medications.
The entrance pupil is typically about 4 mm in diameter, although it can range from 2 mm (f /8.3) in a brightly lit place to 8 mm (f /2.1) in the dark. The latter value decreases slowly with age; older people's eyes sometimes dilate to not more than 5–6mm in the dark, and may be as small as 1mm in the light. [25] [26]
When pupils are dilated, it means that they grow larger in size. This can happen for a number of different reasons, including drug use and arousal. 7 reasons why your pupils may be dilated, from ...
Anisocoria is a common condition, defined by a difference of 0.4 mm or more between the sizes of the pupils of the eyes. [2] Anisocoria has various causes: [3] Physiological anisocoria: About 20% of population has a slight difference in pupil size
The visual system is the physiological basis of visual perception (the ability to detect and process light).The system detects, transduces and interprets information concerning light within the visible range to construct an image and build a mental model of the surrounding environment.
The main characteristic that distinguishes physiological anisocoria is an increase of pupil size with lower light or reduced illumination, such that the pupils differ in size between the two eyes. At any given eye examination, up to 41% of healthy patients can show an anisocoria of 0.4 mm or more at one time or another.