Our visual organ is the eye. It processes the optical stimuli, expressed in the visual registration of shapes and movements, colors, brightness and darkness. The Human 3D software provides a detailed diagram of the human eye along with interactive features.
The visual organ consists of the two eyeballs (bulbi oculi) with the visual nerves (nervi optici) and the corresponding cranial nerve tracts, together with different adjuvant features such as the eye muscles (musculi bulbi), the eyelids (palpebrae) and the lacrimal system with the tear glands (glandula lacrimalis).
The eyes lie protected in the bony eye sockets (orbita).
The light-receiving part of the eye comprises the cornea, the aqueous humor, the lens and the vitreous humor. The light rays entering the eye from the outside are focused through the light receiving parts to form an image. This occurs by the light rays being converted into nerve stimuli which then travel to the sight center in the occipital lobes of the brain (lobus occipitalis) and thus enter consciousness as an image.
In order to see an image in focus, one involuntarily directs the eye to the object such that its image falls on the macula lutea, the “yellow spot”. This is the location of clearest sight (fovea centralis). The farther the objects are from the yellow spot, the more unclear they become. At the place where the optic nerve leaves the eye one cannot see anything. This is called the “blind spot”.
In order to adjust sight to different distances, the lens can refract to different degrees. This process of near-far focusing is called accommodation. It is performed using the cilia muscle. If the eye is to adjust to see something in the distance, the lens bands around the lens tighten and the lens becomes flatter. When looking at something close up, the ring muscle in the cilia organ tightens and loosens the lens. As a result of its elasticity, the lens bends further until the object is focused on the retina.
As a result of the tension in the cilia muscle, the eye becomes tired more quickly when looking at something close up compared to looking at something in the distance. The ability of the pupil, connected to the accommodation, to narrow as the lens bends further supports focusing.
It must be noted that these procedures usually occur in both eyes. In order to avoid double vision, the brain is able to merge the images. This is called fusion.
Find detailed human eye diagrams with interactive features in the Human 3D software.
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