The iris, or iris, is a pigment-enriched structure in the eye between the cornea and the lens that encloses the visual hole (pupil) in the center and serves as a kind of diaphragm for optimal imaging of objects on the retina. Muscles in the iris can regulate the size of the pupil and thus the … Iris: Structure, Function & Diseases
The eye muscles serve the motor function of the eyeballs, accommodation of the lenses, and adaptation of the pupils. The 6 external eye muscles are able to move the two eyeballs in unison and synchronously or to focus on a gaze target. The inner eye muscles are responsible for focusing on near or far vision … Eye Muscles: Structure, Function & Diseases
As early as around the year 1000, an Arab scholar came up with the idea of supporting the eye by means of optical lenses. Around 1240, monks put this idea into practice – the birth of eyeglasses. For centuries, they were the only way to correct defective vision. But in recent years, they have had … Eye Laser and Other Modern Methods
History While regular astigmatism (astigmatism, astigmatism) does not normally change over the course of life, irregular astigmatism can progress steadily. This is especially the case when there is a permanent malformation of the cornea, in which the center of the cornea grows conically forward (so-called keratoconus). If the astigmatism is not corrected, severe headaches must … History | Astigmatism: Blurred Vision
If you have blurred vision both at a distance and at close range, the cause may be a so-called astigmatism. The eye is no longer able to focus the incident light on an exact point on the retina and thus to bring it into focus, but the affected persons see points as blurred lines. Normally, … Astigmatism: Blurred Vision
Symptoms The symptoms of astigmatism (astigmatism, astigmatism) depend on the severity of the curvature of the cornea, since this results in refractive errors of varying degrees. A slight astigmatism is often not noticed by those affected. However, if the astigmatism is more pronounced, the clear astigmatism is noticeable due to blurred vision at near and … Symptoms | Astigmatism: Blurred Vision
The yellow spot, also called the macula lutea, is a small area on the retina through which the visual axis passes. Within the macula lutea is the zone of sharpest vision (fovea) and also of color vision, because the approximately 6 million cone-shaped M, L, and S color sensors are concentrated almost exclusively in the … Yellow 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
What is lens opacity? The clouding of the lens is also called cataract. In Germany, the absolutely most common form is age-related lens clouding. Due to a number of factors, such as injuries, diabetes, radiation and mostly age, clouding of the lens occurs. As a result, vision is significantly reduced. Those affected describe the symptoms … What is lens opacity? | Lens of the eye
Can you see without a lens? The main task of the lens is to adjust the refractive power of the eye. By deforming the lens it is possible to fix individual objects precisely. However, the lens is not the only part of the eye that can bundle incident light rays. It is not the lens … Can you see without a lens? | Lens of the eye
Cataract is typical in old age. From the age of 65, a clouding of the eye lens can be seen in almost everyone. Cataract surgery is the most common operation in Germany and worldwide – in Germany alone it is performed around 500,000 times per year. Complications tend to be rare with cataract surgery. What … Cataract: Symptoms and Treatment
