Most perceptions enter our brains through the eye - conversely, we send messages to our environment through our eyes. Whether we are sad, happy, anxious or angry, our eyes tell that to the other person. In half of all people, there is a statistically limited sight - and many diseases such as diabetes, high blood pressure or migraine also affect the eyes.
Layout and function
The eye is often compared to a camera and this comparison is also very helpful for understanding the structure and function. From the outside you can see in the eye first the iris, which has a different color in each person. Newborns often have blue eyes and the eye color changes in the first 12 months.
Through the iris light falls into the eye, where it meets the lens of the eye. It contracts by itself or is pulled apart by a fine device - depending on whether we look into the distance or near. So she gives a sharp image to the retina, which lines the eyeball from the inside.
The "seeing" on the retina is taken over by two different sensory cell types, the photoreceptors: the cone and the rods. Cones see in color, chopsticks in black and white. On the retina not all the same number of rods and cones are distributed, but there is a spot of sharpest vision (the yellow spot, the macula) with many cones and surrounding districts, in which one sees blurred.
At one point, the blind spot, you can not see anything, there pulls the optic nerve (optic nerve) in the direction of the brain, where then the sensory impressions are processed.
Complaints on the eye
Eye complaints can occur outside of the eye or inside. Common external complaints are itching or burning sensation, a tearing, red or dry eye or the feeling that a foreign body hangs between the eyelid and the connective or cornea. Other "internal" complaints include blurred vision from double vision to loss of vision, pain, pressure inside the eye, or the feeling of walking in the eye.
There are many different ways to detect eye complications:
- Inspection and palpation
- Visual acuity and visual field examination
- Electrophysiological examinations
- X-ray, ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI)
In the following, these examination methods will be presented to you in more detail.
1. Anamnesis: ask for medical history
All complaints can be further limited by specific questions. Thus, a watery eye can itch and burn at the same time or the symptoms can only occur seasonally (for example in the case of a pollen allergy).
Visual disturbances can occur together with other diseases, so in light migraine photophobia and optical hallucinations are described - and a small "stroke" in the eye can be a first warning sign of an impending brain infarct.
These distinctions show the doctor what disease is behind the symptoms.
2. Inspection and palpation: viewing and palpation
In conjunctivitis (conjunctivitis), the conjunctiva is often visibly red and the eye is very watery. A skilled practitioner can use a spatula to fold the upper eyelid so that a foreign body or change under the eyelid becomes visible.
An eye malfunction is examined in which the patient is asked to follow the examiner's finger with both eyes. So a squint position can be revealed. A bruise, an increased intraocular pressure caused by too much eye water or - fortunately rare - tumors lead to a stressed eyeball, which is noticeable especially in the side comparison.
3rd smear with a swab
If there is a suspicion of an infection of the outer layers of the eye, a little swab is taken with a swab, which is then examined for germs in the laboratory.
4. Eyesight for deep insights
The ophthalmoscope allows a view of the retina through the lens - minor bleeding, as occurs in the diabetic eye, and detachment of the retina from the posterior wall of the eyeball.
5. Visual and visual field examination by tests
Who does not know them, the tablets in the doctor's room or the optician with the many letters or numbers? Depending on your eyesight, you will be able to decipher even the bottom row - if not, it may indicate a short or farsightedness. Color recognition tests indicate color blindness or color vision deficiency.
The visual field is checked with the perimeter. The patient gazes rigidly into the device and from the corner of his eye he perceives how tiny lights flash. The fewer lights he sees, the worse it is for his field of vision ordered - as the green star. Imagine the consequences of a field of vision limitation when driving a car!
6. Electrophysiological examinations
The activity of the eye muscles as well as the retina is measurable - with small electrodes that are fixed in the corner of the eye or as a contact lens on the eye.
7. X-ray, ultrasound, computed tomography and magnetic resonance imaging
If there is a suspicion of a tumor or inflammation occurring inside the eye, imaging techniques are used - it is important to clarify whether the ocular border of the eyeball is still intact, especially after road accidents.
In addition to infections of the conjunctiva, which can occur in all age groups, some eye diseases are more likely to occur in childhood, while others, which are more due to wear or chronic diseases of the entire human system, occur in adults. Age-independent injuries to the eye, for example, in car accidents or when something by play or work to the eye.
Eye complaints in children
Coincidental conjunctivitis is often associated with many childhood illnesses (measles, rubella, chickenpox) or a watery eye with hay fever. Even with a long-lasting sinusitis the eyes should be checked because of the proximity to the nose.
Squint is an eye deformity that usually occurs in early childhood and can be successfully treated. The rare but malignant retinoblastoma - a cancer that occurs in early childhood - must be removed as soon as possible.
Eye complaints in adults
Many diseases that damage the entire organism also affect the eye. A typical diabetes consequence is the diabetic retinal damage (retinopathy) - even in high blood pressure, the retina is affected, also promotes high blood pressure, the development of glaucoma (also known as green star).
With advancing age, the elasticity of the eye lens decreases. It can adapt less to near or far vision - and you need reading glasses.
Also often is a lens opacification, which can develop into a cataract. At the same time, sight deteriorates visibly until the relatively harmless gray star surgery becomes necessary.
Another cause of vision deterioration may be age-related macular degeneration, a common yet poorly-known disease of the retina that can lead to blindness. Even in migraine, there is often an eye symptom: Photosensitivity and flashes or rings in front of the eyes are not uncommon.
Regularly to the doctor
Many eye diseases could be treated better if everyone would consider going to the ophthalmologist as a matter of course every day and would not first visit it for complaints. In addition to the prescription of glasses or contact lenses, the doctor can compensate for defective vision by means of a laser correction or an implant. It is individually decided whether the operation can be performed on an outpatient or inpatient basis.
Of course, there is a special procedure for every illness with medication or surgery - you will find that with the respective illness. The German Blind and Visually Impaired Association (DBSV) also offers many tips.
Sunglasses protect the eyes
Sun is good for the soul, but our eyes are harmed by direct sunlight. Connective or corneal inflammation are immediate, cataracts and senile blindness due to macular degeneration the long-term consequences. Preventively helpful is a good pair of sunglasses. The sense of night driving glasses on the other hand is more than questionable.
At high ozone levels, you should be prepared for out-of-home sports activities, as ozone irritates the eyes. If you are an athlete, do not forget your glasses - otherwise you only increase your risk of injury.
For relaxed and beautiful eyes, you can do something specific - especially after working on the screen, your eyes will be glad of an extra dose of attention. In the case of vitamin A-containing food, many of us immediately think of carrots - but there are other foods such as tuna, lettuce or milk that contain vitamin A and its relatives such as lutein.