Visual acuity is the sharpness with which a visual impression from the environment is imaged on the retina of a living being and processed in its brain. Factors such as receptor density, receptive field size, and the anatomy of the dioptric apparatus affect visual acuity in individual cases. Macular degeneration is one of the most … Visual Acuity: Function, Tasks, Role & Diseases
Definition The papilla is an area on the retina of the eye. This is where all the nerve fibers of the retina converge and leave the eyeball as a bundled nerve cord in order to be able to transmit the sensory impressions of the eye to the brain. Anatomy The papilla is a circular area … Papilla
Papilloedema Papilledema, also called congestion pupil, is a pathological bulge of the optic nerve head, which is normally slightly convex. Unlike optic disc excavation, pressure from behind on the optic nerve is increased, causing it to bulge forward. The causes of papilledema can be very diverse. In addition to the optic nerve, numerous arteries and … Papilloedema | Papilla
Synonyms in a broader sense visual hole Definition The pupil forms the black center of the colored iris. It is through this iris that light enters the eye and travels to the retina, where it leads to the signal transduction that is responsible for the creation of a visual impression. The pupil is variable in … Pupil
How big are the human pupils? The size of the human pupil is relatively variable. One of the most important influencing factors is the brightness of the environment. During the day, the pupil has a diameter of about 1.5 millimeters. At night or in darkness the pupil widens to a diameter of eight to even … How big are the human pupils? | Pupil
Pupillary Reflex The adaptation of the pupil to the prevailing light situation is achieved by the so-called pupillary reflex. A distinction is made between the part that receives the information about the exposure and transmits it to the central nervous system (afference) and the part that, after processing this information, leads to the activation of … Pupillary Reflex | Pupil
What can dilated pupils indicate? In darkness, the pupils are dilated to allow as much light as possible to enter the eye. The so-called sympathetic nervous system dilates the pupils. It is particularly active during stress reactions and also increases pulse and blood pressure, for example. In stressful situations, the pupils can dilate accordingly. A … What can dilated pupils indicate? | Pupil
What does “isokor” mean at the pupil? Pupils are called isocor if their diameter is about the same on both sides. Slight side differences of up to one millimeter are still called isocor.Larger differences are no longer isocor, such a state is called anisocor. Since anisocor is an important symptom in a number of diseases, … What does “isokor” mean at the pupil? | Pupil
Synonyms in a broader sense Medical: Corpus vitreum Definition The vitreous body is a part of the eye. It fills a large part of the posterior chamber of the eye and is primarily responsible for maintaining the shape of the eyeball (bulbus oculi). Changes to the vitreous body can lead to visual disturbances in the … Glass body
A blind spot is a small, physiologic, slightly elongated-oval visual field defect caused by the location of the optic disc, the exit gate of the collected optic nerve fibers. In the area of the optic disc, the retina is interrupted so that no light stimuli can be perceived at the site. Normally, the blind spot … Blind Spot: Structure, Function & Diseases
Synonyms Lens oculi Introduction The lens is a part of the ocular apparatus, is located behind the pupil and, together with other structures, is responsible for the refraction of the incoming light beam. It is elastic and can be actively curved by muscles. This allows the refractive power to be adjusted to different requirements. With … Lens of the eye
Physiology The lens of the eye is suspended via fibers (zonula fibers) in the so-called ciliary body of the eye. The ciliary body contains the ciliary muscle. It is a ring-shaped muscle that contracts when tensed. When the muscle is tensed, the zonula fibers relax and the lens becomes rounder thanks to its inherent elasticity. … Physiology | Lens of the eye
