A not inconsiderable number of people suffer from them, fear of it, however, in any case most. After all, who wants to have limited eyesight or even lose it completely in the worst case? But the knowledge about the diseases is mostly limited to generalities. For this reason, the purpose of this article is to shed some light on the subject and provide information about which diseases and visual defects actually exist. What are their symptoms, how do they progress? Which of them can be treated at all, and which not? In addition to the diseases, the article deals with the widespread visual defects such as nearsightedness and farsightedness and other visual defects such as color blindness.
Short-sightedness and long-sightedness
Schematic diagram showing the anatomy of the eye with nearsightedness and farsightedness and after treatment. Click to enlarge. Let’s start with the less serious impairments of the eye. Visual defects can also cause various discomforts in everyday life. The first one is myopia or hyperopia. Myopia or hyperopia cannot in itself cause blindness and should therefore be viewed calmly for the time being. Since the difficulty in recognizing distant or near objects – depending on the form of defective vision – can certainly have an impact on everyday life, it is advisable to consult aids which, depending on the degree of weakness, have a regulating effect on everyday requirements. For a long time, for example, eyeglasses were considered unfashionable, but these times are now rightly over. Instead, many people see the visual aid as a chic accessory. Specialty stores offer a wide selection of different frames and can also help with individual advice. In keeping with the latest fashions, new models are constantly appearing on the market. If you still don’t want to put up with glasses, you can still opt for contact lenses or even have your eyes lasered. Basically, a semi-regular visit to the specialist is of course necessary to observe the development of the visual impairment and in the case of appropriate countermeasures can be taken.
Color blindness
Similar to myopia and hyperopia, this is not a disease, but a visual disorder, as the name suggests. Strictly speaking, however, there are not only color-blind people, but also those who only have a weakness in color perception. Of course, colorblind people have to accept an immense impairment of their everyday life. Much more common than actual color blindness is actually red-green deficiency, which affects between five and nine percent of the male German population, depending on the information provided. In this case, only the perception of the two color tones is difficult because the rods for the perception of the corresponding colors are missing. Incidentally, red-green deficiency is much more common in men than in women. This is because the corresponding genes for color perception are located on the X chromosome, of which women are known to have two, while men have only one. True color blindness, however, means not being able to perceive any colors at all and perceiving the environment only in various shades of gray. In this way, for example, participation in traffic can become considerably more difficult. Apart from gene therapy, which has not yet been sufficiently researched, there is still no cure, by the way.
Inflammation of the eye
Inflammation of the eye is the term used to describe an inflammatory reaction in the area of the human eye. Eye inflammation is relatively common and has a wide variety of causes. Even if we hardly register it: The eye is busy all day defending itself against environmental stimuli of all kinds and pathogens. Often, inflammations in the eye are nothing more than reactions to bacteria and viruses by the immune system. Of course, it must be taken into account that environmental influences such as smoke, drafts or bright sunlight do not necessarily make it easier for the eye to protect itself.
Symptoms of eye inflammation
Although there are quite different inflammations in the eye, the symptoms are quite often similar.What they all have in common is that they are extremely annoying and can be both painful and disabling – of course, because they hinder a not unimportant part of one’s own perception. Typical symptoms can be, for example:
- The affected eye secretes a secretion
- Stinging pain of the affected eye
- Reddened eye
- Swelling of the affected eye
- Increased sensitivity to light
- Strongly veiled vision
The conjunctivitis
Conjunctivitis is the most common disease of the conjunctiva in the eye and should be examined and treated by an ophthalmologist. Admittedly, there are different inflammations caused by the complexity of the eye, which can occur in different places. One of the classic inflammations that can occur in the eye is conjunctivitis, also known as conjunctivitis. In addition to the factors already mentioned, conjunctivitis can also be caused by allergies. But what is a conjunctiva at all? The conjunctiva is ultimately a mucous membrane that is located in the anterior segment of the eye and thus feels in the eye socket. By the way, it is not only looked at during ophthalmological examinations, but during clinical examinations in general. Due to the fact that it is relatively thin as well as well supplied with blood and unpigmented, it is relatively easy to detect changes in the blood through it. In the complex structure of the eye, the conjunctiva has a special function: among other things, it is very important because it distributes the tear fluid over the cornea. If the conjunctiva is inflamed, one often has the feeling that there is a grain of sand in the eye. It feels as if there is a foreign body in the eye, even though this is not the case from a purely objective point of view. However, there are different types of conjunctivitis, between which one must distinguish. There are, for example, allergic, bacterial and viral conjunctivitis, but also non-specific conjunctivitis. Here we briefly show the different symptoms.
Symptoms of allergic conjunctivitis.
Sudden and unexpected tearing and severely itchy eyes dominate the symptoms of allergic conjunctivitis. Swelling of the eyelids can also cause them to droop slightly as a secondary symptom.
Symptoms of bacterial conjunctivitis
Particularly unpleasant, in addition to the usual consequences of conjunctivitis in the bacterial variant, is the fact that there is a strong formation of mucus in the corners of the eyes. Especially in the morning, the eyes are regularly stuck together. The problem here is that bacterial conjunctivitis often occurs in both eyes, as it is contagious.
Symptoms of viral conjunctivitis.
Viral conjunctivitis often does not occur on its own, but is often a result of diseases transmitted by the virus. In flu, measles and chickenpox, for example, the pathogens then pass to the conjunctiva, further tormenting those who are already ill.
Diagnosis and treatment
Conjunctivitis is usually diagnosed by an ophthalmologist. He looks at the eye with a so-called slit lamp and folds the eyelid over to be able to look at the inside of the eyelids. A smear test may be necessary to determine the causes and thus the correct treatment method for the inflammation. Depending on this, the ophthalmologist will then prescribe, for example, an appropriate antibiotic or an eye ointment. Certain eye drops are also conceivable, although some conjunctivitis heals on its own. However, since you can never know this exactly as a layman and conjunctivitis can potentially be contagious, you should definitely consult the expert.
Corneal inflammation (keratitis).
There are also different variants of corneal inflammation, which is technically called keratitis. Again, there is a bacterial and viral keratitis, as well as one caused by fungi. The cornea is particularly susceptible if it has already been damaged. A healthy cornea is usually relatively stable and has an appropriate defense. What is particularly dangerous about corneal inflammation is that the associated infection can spread to other surrounding parts of the eye and damage them as well. For this reason, if corneal inflammation is not treated, serious consequences may occur.One of the most common causes of corneal inflammation is wearing contact lenses for too long – or if they are not cleaned. However, it strongly depends on the type of contact lenses. The symptoms are quite similar to conjunctivitis: Pain, reddened and stuck eyes, and impaired vision are among the symptoms. Here, too, the warning signs of the symptoms should be followed and an ophthalmologist should be consulted. Treatment as quickly as possible is virtually essential. The diagnostic procedures are very similar to those for conjunctivitis: First, the doctor must know about the cause of the inflammation. The way in which the inflammation is medicated is also quite similar. However, in the case of corneal inflammation, surgery may be necessary, for example, if it is the variant caused by fungi and the deeper layers of the cornea are already affected. For this very reason, one should seek treatment at an early stage. If this is the case, the corneal inflammation can usually be cured relatively quickly.
The glaucoma – the glaucoma
Infographic of the anatomy and structure of the eye in glaucoma. Click image to enlarge. Glaucoma is the collective term for a whole range of eye diseases that appear in most sufferers after the age of 40 (unless they are congenital) and, in the worst cases, can lead to complete blindness. Just as with the eye diseases presented so far, it is therefore important here to act in good time. But how does glaucoma develop in the first place? As a rule, the development of glaucoma is accompanied by increased pressure in the eyeball. This occurs when there is more aqueous humor in the anterior chamber of the eye (the area where the lens of the eye is located) than can be drained through the eye’s outflow system. As a result, the aqueous humor in the eye is not replaced often enough. The aqueous humor is so important because it acts as a nutrient provider for the lens and cornea, neither of which have their own blood vessels and for this reason rely on the aqueous humor as a nutrient provider. In addition, the aqueous humor serves as an optical medium. Therefore, if it accumulates and can no longer be exchanged properly, the pressure in the eye increases. The problem caused by the increased pressure should not be underestimated. This is because the supply of blood, and thus also of urgently needed nutrients, to the eye falls short. This leads to typical restrictions in the field of vision. If one notices these, one should regard them with the necessary seriousness and react absolutely with a visit of the specialist. Shockingly, glaucoma is still one of the most common causes of blindness. Unfortunately, two thirds of those affected notice far too late that they are ill. In total, there are still 800,000 people who suffer from glaucoma on average.
Symptoms of glaucoma
That’s why it’s so important to know the symptoms of glaucoma so you can act on them. As mentioned earlier, narrowing of the visual field is very common. This narrowing regularly happens in an arcuate fashion that should be cause for alarm. Other deteriorations of vision are also conceivable, such as loss of visual acuity and contrast. In the event that the elevated eye pressure has existed for a long time, there is a good chance that edema in the eye will result in refractions that can be seen as colored rings or halos when looking into brighter light sources. Common symptoms, for example, in the case of a glaucoma attack include severe headaches, nausea and vomiting, and even cardiac arrhythmias and collapse.
Treatment for glaucoma
In any case, glaucoma must be treated by a doctor. This can be done both with medication and with surgical measures, depending on the case. It depends entirely on the form of glaucoma and the causes behind the disease, which measures can lead to success.
Scotoma – loss of the visual field
Visual field loss can be present on one side or affect both eyes. There are also visual field losses that limit near vision and those that affect distance vision. Another extremely unpleasant variant of the eye disease is the suffering of a so-called scotoma. This word refers to the phenomenon when vision in a certain area of the visual field deteriorates or possibly even fails completely.It is noteworthy that this can occur both in the center field of view and in the peripheral areas. It is the case that the loss is subjectively noticeable. In the worst case, the reduction of vision can even lead to partial blindness. Various factors can be responsible for this loss or reduction. It is difficult to localize the causes properly. This is because diseases in every conceivable section of the visual pathway itself can be responsible for the reduction, but other diseases could also be possible triggers. There is a distinction between different forms, which we would like to present here very briefly:
- Relative scotoma: The visual impression is indistinct, hazy and a clear recognition is difficult.
- Absolute scotoma: Complete loss of the ability to see anything left in the area of the scotoma.
- Distortion: the objects in the corresponding area are perceived only distorted.
- Homonymous visual field loss: hemifacial visual field loss on the same side in both eyes. There is also heteronymous visual field loss, in which the sides are different.
- Hemianopsia: hemifacial visual field loss.
A specialist examination of the phenomenon is necessary, especially if the scotoma meets some conditions. For example, if there are accompanying symptoms such as vomiting, nausea, speech disorders or disorientation, flashes of light, a flicker or similar symptoms, it is essential to seek medical help.
Age-related macular degeneration
Schematic diagram showing the anatomy of the eye and the difference between healthy eye and macular degeneration. Click to enlarge. Macular degeneration, or degeneration of the retina at the back of the eye, is a disease that can occur in general, but is most common, and by far the most common, in older people. In the general course of the disease, there is progressive loss of vision in the central visual field, while the peripheral visual field remains unaffected. The numbers concerning the affected persons are quite worth mentioning: Altogether about three million people in Germany are affected by age-related macular degeneration. Consequently, this is the most frequent cause of blindness at all. There are basically two different types of age-related macular degeneration: On the one hand the dry variant and on the other hand the wet variant. First we come to the dry one, which is also by far the more frequent variant. The degradation of the visual ability due to the loss of photoreceptors occurs here step by step. At the beginning, the visual ability is only relatively little restricted, however, the restrictions become more and more noticeable in the course of time. The wet variant, on the other hand, usually develops from the dry variant, but progresses much faster. In addition, it is irreversible and causes a permanent loss of vision, which is more difficult to stop than in dry macular degeneration. A basic cure of the disease unfortunately does not exist until today. However, it is possible to slow down or stop the progression of the disease. Again, an early diagnosis is the only way to be able to ensure an extensive preservation of vision. The fact that people who have reached the age of fifty-five have regular check-ups with their ophthalmologist is a helpful way to prevent worse from happening.
Retinal detachment or ablation retinae.
Schematic diagram showing the anatomy and structure of the eye with retinal detachment. Click to enlarge. In retinal detachment, which is not without danger, the retina detaches from the choroid that lies beneath it. Retinal detachment is therefore an emergency, because the moment it is detached, it is no longer supplied with the necessary nutrients by the choroid as before. The problem is that the light-sensing cells remain unsupplied and therefore die in a very short time if they are no longer supplied. The retina and choroid are not fused together, but rest on each other only due to physical forces. For this reason, it is important to register the symptoms as quickly as possible and to react accordingly.Flashes of light at the edge of the visual field, the perception of black spots in the visual field (so-called sooty rain), or a partial loss of vision should definitely be investigated.
Conclusion
One of the few commonalities among the diseases and phenomena presented is that an examination by a knowledgeable ophthalmologist is almost always the safest way to prevent lasting damage to the eye or at least to take the necessary measures to mitigate any consequences.
