The eyes, our windows to the outside world, are home to probably the most important sense for many people: the sense of sight. The eyelid, which encloses the eyes, is often given attention only when it is conspicuously made up, or involves disease symptoms. It belongs to the rather inconspicuous parts of the body. Thereby the eyelid takes over some central tasks, which should not be underestimated despite its sensitive design.
For example, it is responsible for protecting the eye from foreign bodies such as dust, too strong light or contact. The incidence of light is also controlled by the closing movement of the eyelid. Its composition as well as tasks. Susceptibilities are highlighted in more detail below.
What is the eyelid?
The eyelid is a thin layer of skin that protects the eyeball inside the eye socket. It is divided into an upper and a lower eyelid, each of which can be opened and closed by muscle movement. The muscular contraction that controls the incidence of light on the retina of the eye is called blinking.
When we sleep, the eyelid usually remains closed and switches off the entire sense of sight. This helps us to switch off for the night and enter a resting state. Despite its thin and sensitive construction, the eyelid consists of a tight tie of muscles, connective tie and glands. They run beneath the skin in a particularly concentrated manner. They supply it with nutrients make it particularly flexible and mobile.
The gap between the upper and lower eyelids is called the palpebral fire and is covered with a fringe of hairs that keep extra small parts from entering the eyeball. They are known to us as eyelashes.
Many animal species, especially mammals, have a similar structure of the eyelid with congruent functions. In addition, some have a third eyelid called the nictitating membrane. In humans, the nictitating membrane is also present, although it is not visibly developed and its function is not significant.
Although the eyelid is not considered a prominent organ, it has two immensely important functions. At first it is the
Protective wall, shielding the sensitive eye from the outside world. Through its muscle contraction it is able to close the eye specifically and to protect it from foreign bodies, dust, dirt, too strong light or even too extreme temperatures.
Too much heat can dry out the eye, too cold air damages the moisture of the sensitive eyeball. The rim of eyelashes at the edge hem of the eyelid acts as an additional filter that can keep out minute particles and secure the closure of the eyelid.
The muscles of the eyelid are among the fastest muscles of our body. They are associated with a reflex that automatically closes the eyelid when startled. This is called the reflex closure of the eyelid, which reacts within fractions of a second. Also, when objects move toward our eyes, or too bright light shines on them, the eyelid closes automatically.
By very fast muscle contraction, which is also called blinking, foreign bodies that have already penetrated the eye can also be transported to the edge of the eye. They can then be flushed out by the tear fluid without further injuring the eye.
The Moistening the eye second task of the eyelid is to keep the eye moisturized by this tear fluid. Each muscle movement ensures that the eyeball is moistened evenly. This moist surface not only helps to cleanse the eye. On it, the eyelids slide better and faster for optimal protection of the delicate cornea on the eye.
In particularly dry environments, such as hot summer days or heating air, we blink significantly more often to keep the eye moist, usually even unnoticed. Even during sleep, the eye continues to be evenly moistened by the closed eyelids.
The tasks of the eyelid at a glance:
– Protection of the eye from external foreign bodies and pollution – Reflective closure of the eyelid – Moistening of the eye
The eyelid closes the eye socket, in which the eyeball is embedded, to the front. It can be completely closed to efficiently prevent foreign bodies and even liquids from entering the interior of the eye. However, the two eyelids are not developed to the same size.
The upper eyelid is slightly larger than the lower eyelid and can also be opened wider to allow a wider upward angle of vision. The eyelashes, which are found at the edge of both eyelids, are called cilia in technical language. On the upper eyelid they are much denser and longer. At their base are also found the glands that supply the eye with nutrients. Furthermore, the eyelid is divided into an outer. Inner eyelid subdivided.
→ The outer eyelid consists of a very thin layer of skin and includes the ring muscles that can open and close the eye. → The inner eyelid on the other hand, is made up of several components. Its main component is the tarsus, a connective tie plate that is slightly bent in the shape of the eye.
The eyelid is delimited at both ends by the corners of the eye. The corners of the eyes are not symmetrical. The inner one is rounded and contains the lacrimal points and the lacrimal lake, which can be seen as a small bulge. The outer corner of the eye runs to a very acute angle.
The shape of the eyelids is a distinctive sign that is used especially in describing body types of different cultures. The almond-shaped eye of Asian people is classic.
The reason for the differently perceived eye shape is a double eyelid crease, which does not occur genetically, especially among Europeans. The Asian eye appears narrowed. Smaller than the European. The eye does not lose anything in its function due to the changed shape. Nevertheless, in countries such as South Korea, the European eye shape is considered the ideal of beauty, which is pursued with the help of cosmetics or cosmetic surgery.
Even beyond Asian culture, large eyes are considered an ideal. They appear open, outgoing and friendly and are especially popular with women. Small children often trigger a cuteness effect with their large, spherical eyes, which captivates adults.
The effect can also be observed in babies of mammals. Women strive to achieve this ideal by optically lengthening the eyelid with the help of cosmetics, thereby seemingly enlarging the eyes. Larger as well as darker pupils have a similar effect, which works detached from the eyelid.
Diseases, complaints& Disorders related to the eyelid
Due to its high concentration of muscles, ties and glands, the eyelid is very sensitive to the effects of disease. Accordingly, a variety of diseases and complaints can occur. Puffy eyes are not an isolated phenomenon. Occur at irregular intervals in every human being. The reason for this is the outer eyelid. It can absorb moisture and fluids from the environment, causing it to swell comparatively quickly. Especially after getting up after several hours of sleep, many people therefore have swollen eyes.
Since during sleep is not blinked, the eye is continuously surrounded with fluid, which can be absorbed by the outer eyelid. Even after crying, the surrounding skin of the eye swells strongly and reddens. Leaking body fluid is partially absorbed if it has not been dried off beforehand and makes for unsightly "weepy eyes".
Frequent and strongly swollen eyes can also indicate malnutrition, which is characterized by too many preservatives and sodium.
Against swollen eyes it helps to cool the skin of the eye slightly, or to supply it with moisture from the outside, for example with cucumber masks. Creams and ointments should be avoided if they are not explicitly designed for eyes. The sensitive eyelid can be quickly irritated by perfumed substances and react with inflammation and redness.
Probably the most common complaint is a movement disorder of the eyelid. It may appear suddenly overnight or due to an allergic reaction in the case of swelling, but it may also subside just as quickly. However, movement disorders such as uncontrolled eyelid twitching can also be congenital. Be brought about by a malposition of the eyelid.
If they are not genetically predisposed, mineral deficiencies or an unhealthy lifestyle can also be the reason for the complaints. Since the organ of the eye requires a high concentration of nutrients throughout the day, a balanced and relieving lifestyle is therefore important.
Paralysis can also affect the eye. If there is a nerve disorder, for example due to medication or a stroke, parts of the face may become droopy. Often the muscles of one half of the face are affected in this case. The cheek and eyelid hang down visibly and are severely restricted in their function.
In addition to movement disorders, the eyelid, like the eye itself, can also be affected by a variety of Inflammations be affected. The widespread conjunctivitis can also spread to the eyelid. It then affects especially the edge of the eyelid. Is called blepharitis.
Also the Stye is widespread. This is an acute inflammation that is caused by bacteria. They can be transmitted to the eye by unclean hands. It affects the glands on the eyelid and causes a collection of pus, which can form an abscess.
Usually the stye resolves itself after a few days. In case of persistent inflammation, however, an ophthalmologist should be consulted.
Internal strabismus in children
A known malposition of the eye is the so-called Strabismus. It can be particularly common in young children between the ages of two or three. In most cases, however, it is still harmless in the early years of life. Is merely a deception.
With the growth and formation of the bridge of the nose, it disappears with the age of the child. However, if the squinting still occurs after this period, an ophthalmologist should be consulted. Early recognized permanent misalignments can still be corrected particularly well in young years.
If the necessary treatment is not given, one-sided visual impairment or severe disorders can occur, which can limit the three-dimensional field of vision of the child.
tumors& Cysts: Besides abscesses, tumors or cysts can also affect the eyelid. They particularly restrict the movement of the eyelid. May cause the eye to dry out or attack its nutrient supply. A parasite infestation can also occur due to a lack of hygiene. Sickness of the eye as a whole. Again, a visit to the ophthalmologist is the best treatment. Eye misalignments: Eye deformities occur especially due to hereditary diseases. An oblique position or the nasal fold of the eyelid, for example, are very prominent in both Down's syndromes. In individual cases, the eyelid folds themselves can also be strongly keratinized and deformed, or even completely absent. Xanthelasma: The effects of a lipometabolic disorder are so-called xanthelasma, which are manifested by yellow or red fat deposits on the edge of the eye. They usually occur on both sides of the face on the nasal side of the eyelids, and cannot be treated retroactively. Ectropion: Disturbances of the shape of the eyelid can be caused for example by a break of the eyelid plates, the so-called ectropion. In this case the eyelid bulges outwards. These deformations can occur due to scarring or as a result of eye surgery.
An overview of common and typical disorders:
– chalazion, abscesses, cysts – inflammation of the eyelid margin tumors – xanthelasma – eyelid malpositions& malformations – ectropion
Common questions& Answers
Dust in the eye?
Despite the protective mechanism of the eyelid, it often happens that foreign bodies or dust get into the interior of the eye. You can easily remove small particles from the eye yourself by closing the eye and lightly stroking the eyelid toward the nose. Be careful not to put too much prere on the eye and to carefully disinfect your hands beforehand, otherwise you may further irritate it or cause inflammation. A moist cloth supports the tear fluid, which can flush out the foreign body in this way.
Foreign body in the eyeball, what to do?
If massive foreign bodies have entered the eye, which cannot be removed by simple stroking, or if there is an injury to the eyeball, avoid eye contact at all costs. Stubborn foreign bodies that have penetrated or injured the eyeball or conjunctiva should be left in the eye and professionally removed by a specialist.
Also abscesses like the sty should not be squeezed with the fingers under any circumstances. Bacteria can quickly penetrate open wounds, which can cause inflammation in the sensitive eye.
Are dark circles unhealthy?
So-called dark circles are present in every human being. They are manifested by a dark, usually blue coloration, which usually appears just below the eyes and which varies in severity from person to person. Affected people usually appear sick or sunken, but the appearance of dark circles does not necessarily indicate a disease. In most cases they are harmless, short-lived and easy to cover cosmetically.