Function of the dermis
The main function of the sclera is to protect the eye, or rather, to protect the sensitive interior of the eye. Especially the vulnerable choroid, which is located underneath the sclera, is protected by it. It needs this protection because it is responsible for the blood supply of the eye and therefore has many veins.
In order not to disrupt this blood flow, the sclera has numerous openings which do not affect its protective function. The protective mechanism is multifaceted and begins with the buffering of mechanical influences on the eye. Furthermore, the dermis prevents sunlight from damaging the eye by preventing direct exposure.
Furthermore, the sclera has the function of giving the eye its shape. The pressure of the sclera against the intraocular pressure creates the spherical shape of the eyeball. Furthermore, the sclera has the function to indicate the general state of health of the patient. The coloration of the normally white sclera plays a special role, since it can change color depending on the disease. This topic could also be interesting for you: How does vision work?
CLINIC: Diseases of the dermis
A leather skin inflammation, also called scleritis, is an inflammation in the eye that can occur on one side or both sides. It is also possible that it is chronic or recurrent. It is a rather rare eye disease, but it is not to be taken lightly, as in the worst case it can damage vision.
For this reason it should always be treated by an ophthalmologist. People aged 40-60 years are particularly common, with the inflammation occurring more often in women than in men. A distinction is made between anterior and posterior inflammation of the dermis.
The anterior one is easily recognizable from the outside, whereas the posterior one must be diagnosed with the help of an ultrasound device. The cause of the inflammation of the leather skin is rarely viruses or bacteria, mostly it is an autoimmune disease.Rheumatism or Crohn’s disease can serve as examples of an autoimmune disease. Those affected complain of a strong, stabbing pain in the eyes, which is often felt in the form of a pressure pain.
This pain can be so strong that it does not let the patient rest all day and all night. Furthermore, swelling of the dermis is also a symptom. This swelling, which is visible from the outside, also causes the pain.
Furthermore, a discoloration of the dermis occurs in case of inflammation. The white color makes way for a dark red to bluish discoloration. In addition, there is usually unclear vision or impaired vision due to increased tear flow.
A red sclera or a reddening of the eyes is usually caused by the blood vessels of the conjunctiva and the sclera being dilated and more strongly supplied with blood. For this reason, the actually whitish to transparent sclera appears red, because the choroid is located directly under it. The redness is easily visible in the front part of the eye and can occur on both sides as well as on one side.
A redness can have a harmless background that can be easily corrected, such as irritation or overexertion. The causes are usually lack of sleep, dust, dry air, cosmetics, air conditioning, strong sunlight, etc. If, in addition to the redness of the eyes, there is also a permanent watering of the eyes or constant itching, which is also expressed by pain, an ophthalmologist should be consulted, as the sclera may have become inflamed.
In the case of a yellow sclera, which is immediately visible from the outside, the eye itself is not directly affected, but organs in the body. Thus, a yellow-colored sclera is an early sign of illness. It can be differently colored from a slight yellow tinge to a deep yellow discoloration.
The yellow-brownish bile pigment bilirubin is responsible for the discoloration. It is formed when the hemoglobin, which colors the blood red, is broken down. Bilirubin is not water-soluble and is converted in the liver so that it is now water-soluble.
It is finally excreted for the most part via the bile ducts and the intestine in the stool. If there is a disorder in this process, the bilirubin cannot be excreted properly and is deposited in the blood. This accumulation in the blood causes the normal skin and mucous membranes to turn yellow in addition to the dermis.
Typical diseases for a yellow dermis are therefore diseases of the liver, such as hepatitis or alcoholism. Bile can also be affected, and malnutrition or undernourishment can be present. If the respective disease is successfully cured, the dermis will also regain its original white color.
