Contributions by Dr. Dominique Mustur, MD

The iris is the colorful part of the eye and is as individual as a fingerprint. The so-called iris or "colorful aperture" of the eye can appear in many shades of gray, green, blue or brown due to an individual pigment distribution. Regardless of its color, the iris regulates the amount of light entering the eye through two muscles. They...

The middle shell consists of three sections with specific functions. The iris adjusts the incidence of light. The ciliary body produces aqueous humor and regulates the curvature of the lens for near or distance vision. The choroid, which is rich in blood vessels, supplies the retina with oxygen.

The lens of the eye focuses the light entering through the pupil. With approximately 10 to 20 diopters of the eye's total refractive power (of about 63 diopters), the eye lens - along with the cornea - is an essential component of the eye for sharp vision. The human lens is an elastic converging lens, which is formed by the inner eye muscles and...

The lens ligaments - also called zonular fibers - are elastic fibers arranged in a spoke-like pattern around the capsule in which the lens of the eye is located. They hold the lens in position and transmit the movements of the ciliary muscle to it. Thus, they are an important part of accommodation. During lens replacement, both the ciliary muscle and the...

The external eye muscles are responsible for the movements of the eyes, i.e. changing the direction of gaze. They attach to different parts of the eyeball. Humans have four straight and two oblique eye muscles. Their interaction is complex and therefore they are able to perform all rotational movements of the eye in all directions. Unlike the internal eye muscles...

The sclera forms the outermost layer of the eye, it is "the white of the eye" that can be seen from the outside around the pupil and iris. It is therefore also called the white skin of the eye. Called "sclera" in Latin, the sclera protects the eye from external influences and ensures that it keeps its shape. The sclera...

The choroid is located between the sclera and cornea and extends over the entire posterior part of the eyeball. It has a high density of blood vessels and supplies the retina with nutrients and oxygen. The choroid merges with the ciliary body in the anterior segment of the eye. In addition, the choroid is also responsible for the thermal regulation of the retina...

While the retina is supplied by the choroid from one side, blood vessels also lie directly on the back of the eye - the retina. This network of vessels comes from the central artery (arteriole), which emerges directly from the optic nerve, and covers the entire retina. The more branched these vascular branches become, the smaller the diameter...

The vitreous body fills most of the interior of the eye and thus sits between the lens and the retina. Consequently, light entering through the pupil and lens must pass through the vitreous before it reaches the retina. The vitreous body consists of a gel-like substance that is 98 percent water, as well as sugar and protein (hyaluronic acid) and a...

The retina is responsible for converting light entering the eye into nerve impluses. The retina is very sensitive to light and lines the inside of the eye. It is occupied by approximately 127 million light receptors. The retina consists of a total of six cell layers with different functions. The light-active sensory cells are the so-called cones and rods. While the cones...