Do you know the most common vision disorders?
The most common vision disorders are refractive errors: long-sightedness, short-sightedness and astigmatism, corrected with glasses, lenses or laser surgery.
Long-sightedness
Long-sightedness, medically also known as hypermetropia or hyperopia, causes poorer vision at short distances. The light rays that fall on the cornea converge behind the retina, where they form the focal point. To correct this vision defect, the focal point has to be moved forward, which is what lenses with plus dioptres are for.Long-sightedness is difficult to detect during routine check-ups with a general practitioner, as it is a vision defect that affects near vision. An examination by a specialist is therefore necessary. In the case of lower dioptres, this refractive error is corrected with reading glasses or convex lenses, or alternatively with surgery.
MUDr. Ivo Ďurkovič, MPH, chief ophthalmologist at iClinic, says that “people with hypermetropia are also more prone to presbyopia, which is characterised by a reduced ability to focus at very short distances.”
Short-sightedness
Short-sightedness, medically known as myopia, is the most common refractive error: light rays are focused in front of the retina, creating a blurred image. A short-sighted person sees nearby objects clearly but, depending on the degree of the refractive error, has difficulty recognising objects further away. Short-sightedness can also be detected during routine medical check-ups, as patients are usually tested with an illuminated eye chart placed several metres away.Myopia can be classed as a childhood condition. Although only one per cent of newborns are affected, the number of children with myopia rises sharply once they start school, and today one in five adults is short-sighted. Although genetics is one of the risk factors for short-sightedness, in recent years today's lifestyle has become a far greater problem in Slovakia, as in other developed countries. Children get their hands on mobile phones and tablets far too early and can sit in front of the television for hours on end.
Another negative trend is that both children and adults generally get much less exercise and spend far less time outdoors. As a result, our eyes adapt to looking at close objects, and the ability to focus at a distance does not develop sufficiently.
Laser eye surgery corrects the vision defect permanently
Heredity plays the greatest role in the development of short-sightedness, but it can also be caused by disproportions arising during the development of the eye or by an unhealthy lifestyle. Myopia is corrected with prescription glasses or contact lenses with minus dioptres. These correct the vision defect by moving the focal point backwards. The only guaranteed way to get rid of short-sightedness permanently is laser eye surgery.
Astigmatism
Astigmatism, a common refractive error, means that part of the image we see is blurred and unclear. Compared with a healthy eye, the surface of the cornea is more curved in one plane than in the other, so incoming light is refracted differently in areas of different curvature, which affects the image that is formed.
The main symptoms of astigmatism are a hazy, unclear or distorted image. The glasses or lenses used to correct astigmatism contain a so-called cylinder to refract light and are called toric. Contact lenses are the most suitable visual aid for astigmatism, but astigmatism can only be eliminated by laser surgery. One of the most popular laser methods for getting rid of astigmatism is, for example, the revolutionary, painless third-generation ReLEx SMILE 3D method.
Presbyopia
Presbyopia is a common phenomenon in people over the age of 40 to 45. It is associated with the natural ageing of the lens. Its reduced ability to accommodate means that the eye cannot focus on very close objects. To read a text, a person tries to hold the phone display or book as far away from their eyes as possible, but their arms are often “too short” – hence the name “short arm syndrome”. The near point of accommodation gradually moves away from the eyes, from 20 cm at the age of 40 to 30 cm at 45 and 40 cm at 50.
Presbyopia is not the same condition as long-sightedness, but it very often develops in people who are already long-sighted. Uncorrected presbyopia progresses until the age of 60, when the patient's condition usually stabilises and no longer worsens. If you notice symptoms of presbyopia and find it difficult to read text at a distance that used to cause you no problems, talk to your ophthalmologist about the possible solutions.
Presbyopia can be corrected with reading glasses, but also with surgical methods that replace the natural lens with an artificial one. Lens replacement can also correct other refractive errors and eliminate the risk of cataract.
Besides refractive errors, eye diseases that are not related solely to how light is refracted onto the retina are also very widespread. These include cataract and glaucoma.
Cataract
Cataract is an age-related eye disease. It is caused by ageing of the lens, which is why it is very common in patients over 65. It manifests as clouding of the lens, and the previously clear lens takes on a greyish tint. If left untreated, it can cause blindness. Cataract is in fact the most common cause of blindness worldwide. It should be added, however, that blindness caused by cataract mainly affects less developed and poorer countries, where people cannot afford surgery or where there are no clinics able to remove cataracts.
A specific feature of cataract is that even if you lead a truly exemplary lifestyle, you will not necessarily avoid it. You can, however, reduce the risk indirectly: a balanced diet with a sufficient intake of vitamins and minerals, regular exercise, not smoking and avoiding excessive alcohol consumption protect you against other diseases that can in turn influence the development of cataract. A typical example is diabetes, which is often a direct cause of cataract.
Besides visible changes in the lens, the symptoms of cataract mainly include vision problems such as unclear, hazy or blurred vision and double or even triple vision.
Cataract treatment
At present, cataract treatment is limited to surgery, as there is not yet any effective medication to cure it. The operation consists of replacing the old lens with a new, artificial one. Cataract surgery is a completely routine and extremely safe procedure at our clinics. Some methods of cataract surgery are covered by health insurance companies, while others require an additional payment.
Glaucoma
Glaucoma is a serious eye disease in which the optic nerve – whose task is to transmit visual information from the eye to the brain – gradually dies off. After cataract, it is the second most common eye disease causing irreversible blindness. Glaucoma can develop in the eye for years without any symptoms. Only a complete eye examination can detect it in its early stages, which is why regular eye examinations are a very important basis for successful prevention.
There are two main forms of glaucoma: primary glaucoma, which can be open-angle or angle-closure, and secondary glaucoma, which develops as a result of another disease.
Risk factors and treatment options for glaucoma
The greatest risk factor for glaucoma is age, but other factors are also known, such as heredity, low blood pressure, cold extremities (vasospastic syndrome), migraine, smoking, corticosteroid use, diabetes and vascular diseases. Glaucoma can also appear after an eye injury.
High intraocular pressure is considered the main cause of glaucoma, and treatment focuses primarily on lowering it. In the early stages, glaucoma is treated mainly with eye drops that lower the eye pressure. If the drops do not help, the second option is trabeculectomy or selective laser trabeculoplasty, both of which also aim to open up the drainage pathways. The last option is a surgical procedure under local anaesthesia, in which an artificial connection is created between the inside of the eye and the subconjunctival space, into which the aqueous humour then drains.
In secondary glaucoma, treatment focuses on eliminating the underlying disease; once it has been cured, the glaucoma also disappears in most cases.
Eye disorders caused by eye inflammation
Eye inflammation caused by bacteria or viral infections is common especially in groups of children, where it spreads quickly because it is contagious. People with allergies are also at risk, as bacteria and viruses affect them more strongly due to their weakened immunity. In addition, during an allergy patients often rub their eyes involuntarily, which again increases the risk of bacteria or viruses being transferred into the eye from unclean hands.
In addition to discomfort, itching and a scratchy feeling, eye inflammation can also cause vision problems. It is often the cause of hazy or unclear vision. The problem is usually resolved with antibiotics or antiseptics in the form of drops, tablets or ointments.
Dry eye syndrome
Dry eye syndrome is one of the most common eye diseases. It affects more than 15% of the world's population, so it is entirely appropriate to classify it as a lifestyle disease of the third millennium. In most cases it “only” affects quality of life, but in exceptional cases it can even cause blindness. The condition is caused by insufficient tear production or poor tear quality.The syndrome manifests as burning and irritated eyes, impaired vision, eye fatigue or the need to blink more often. Paradoxically, excessive tearing can also be a symptom of the syndrome.
Several factors can contribute to dry eye. The most common include:
- age
- an unhealthy lifestyle
- the environment in which a person spends long periods – dry air, air conditioning, draughts, smoky rooms
- frequent and prolonged computer work, watching TV
- long hours of driving
- working, studying or reading in poor light
- systemic diseases such as diabetes, autoimmune diseases and rheumatoid arthritis
- previous eye injuries and inflammation
Rest, special eye drops or artificial tears are the most common ways for patients to get rid of dry eye syndrome.
Do you feel that some of the symptoms of the most common eye defects and diseases described above apply to your eyes too? Don't hesitate to get in touch with us as soon as possible. When it comes to diagnosis and subsequent treatment, the sooner a vision defect or eye disease is identified, the easier it is to deal with.
