Eye diseases: causes, symptoms and treatment

The classic anomalies of the eye in the form of defective vision

Classical visual defects are not eye diseases in the strict sense, but are caused by abnormalities in the eyes that result in those affected seeing less well than people with healthy eyes:

Short-sightedness (myopia)

Short-sightedness, medically known as myopia, is an abnormality of the eye in which distant objects appear blurred, while close objects can be seen clearly. The cause is usually an elongated eye shape, which means that light is not focused correctly on the retina, but in front of it. In many cases, the change is genetic and is particularly common in children, but it can also be acquired. Symptoms include blurred vision in the distance, frequent squinting of the eyes and headaches. Those affected often suffer from reduced visual acuity at dusk or at night (night blindness). Correction is achieved with glasses, contact lenses or surgical treatment such as laser eye surgery. In severe cases, lens implantation may be necessary.

Farsightedness (hyperopia)

Farsightedness, also known as hyperopia, is an abnormality of the eye in which close objects appear blurred, while objects in the distance are usually perceived clearly. This is often caused by the eyeball being too short or the cornea being too flat, which means that light is not focused directly on the retina but behind it. Farsightedness can be genetic and often occurs in childhood. Symptoms include headaches, tired or watery eyes and difficulty reading or working at short distances. In severe cases, distance vision can also be affected. Correction is made with glasses or contact lenses. Surgical treatment such as laser eye surgery or lens implantation is a permanent solution. In older people in particular, long-sightedness is exacerbated by the natural ageing of the lens of the eye.

Astigmatism (curvature of the cornea)

Astigmatism is a common abnormality of the eye in which the cornea is not evenly shaped. Instead of a perfect spherical shape, it tends to be oval, which means that light is refracted in two different directions and does not land precisely on the retina. This causes blurred or distorted vision both near and far. It is usually caused by genetic factors and can occur as early as childhood. Symptoms include headaches, tired eyes, blurred vision and problems perceiving fine details. Correction is made with special glasses, contact lenses or surgical treatment such as laser eye surgery.

Presbyopia (presbyopia)

Presbyopia is a natural change in the eye that usually occurs from the age of 40. The lens loses its elasticity over time, making it increasingly difficult to focus on close objects. Those affected notice that they have to hold books or smartphones further away from their eyes in order to see clearly. Other symptoms include tired or watery eyes and headaches after prolonged reading. This visual impairment affects almost everyone in the course of their life, as it is not a disease but an age-related anomaly. Reading glasses, varifocals or contact lenses can be worn to correct it. Those who prefer a permanent solution can resort to modern procedures such as PresbyMAX or lens implants.

Night blindness with too little light

Night blindness, medically known as nyctalopia, is a visual disorder in which vision is severely impaired at dusk or in the dark. The cause is usually a malfunction of the photoreceptors in the retina, in particular the so-called rods, which are responsible for twilight vision. In many cases, night blindness is genetic, for example due to albinism or retinitis pigmentosa. However, it can also be acquired, for example due to vitamin A deficiency or certain eye diseases such as glaucoma. Symptoms manifest themselves in a greatly reduced ability to see in poor light conditions, difficulties in recognizing contrasts and a delayed adaptation of the pupil to darkness. There is no direct cure, but vitamin supplements or special glasses can help. If there is an underlying disease such as cataracts, surgery can alleviate the symptoms.

Common diseases of the eye

More or less rarely, however, patients are also affected by serious, permanent eye diseases. The most common eye diseases are

Cataracts – the most common cause of blindness

Cataracts are an eye disease in which the natural lens of the eye becomes increasingly cloudy. This leads to a gradual deterioration in the quality of vision and can lead to blindness if left untreated.

Causes:

• Mainly age-related changes (common from around 60 years of age)
• Genetic predisposition
• UV radiation and smoking as risk factors
• Metabolic diseases such as diabetes
• Injuries or certain medications (e.g. cortisone)

Symptoms:

• Blurred, cloudy vision, as if there is a veil over the eyes
• Light sensitivity and glare in bright light
• Limited color vision – colors appear paler
• Poorer visual acuity, especially in low light

Treatment:

• Surgical treatment is the only effective solution
• The cloudy lens is replaced with an artificial lens
• The procedure is minimally invasive, quick and usually painless

Glaucoma – the silent thief of sight

Glaucoma is a serious eye disease that can lead to blindness if left untreated. It is usually caused by increased intraocular pressure, which damages the optic nerve. The disease often goes unnoticed for a long time as it progresses gradually. The first signs are a restricted field of vision and increased sensitivity to light. Those affected often only notice late on that their vision is deteriorating. Early diagnosis is crucial, as the damage caused cannot be reversed. Glaucoma is treated with eye drops to reduce pressure, laser therapy or surgery to improve the drainage of the eye fluid.

Macular degeneration – when visual acuity diminishes

Age-related macular degeneration (AMD) is a retinal disease that mainly affects people over 50. The photoreceptors in the macula, the area of sharpest vision, degenerate, leading to a gradual loss of central visual acuity. The first signs are blurred vision, distorted lines and difficulty reading. There are two forms: dry AMD, which progresses slowly, and wet AMD, which leads to vision loss more quickly. The causes are genetic factors, smoking and UV radiation. There is no cure, but special medication, laser therapy and dietary supplements can slow down the progression.

Diabetic retinopathy – damage caused by diabetes

Diabetic retinopathy is a retinal disease that occurs as a result of diabetes. High blood sugar levels damage the fine blood vessels in the retina, leading to circulatory disorders and vascular constriction. Those affected often do not notice any symptoms at first, but later experience blurred vision, dark spots in the field of vision or reduced visual acuity. In advanced cases, bleeding or retinal detachment can occur, which can lead to blindness if left untreated. The best prevention is good blood sugar control. The disease is treated with laser therapy, injections of medication or, in severe cases, surgery.

Keratoconus – the irregular deformation of the cornea

Keratoconus is a progressive abnormality of the cornea in which it becomes thinner and deformed in a cone shape. This leads to distorted, blurred vision and increasing sensitivity to light. The exact cause is not fully understood, but genetic factors and frequent eye rubbing play a role. The first symptoms usually appear in adolescence and worsen over the years. In the early stages, glasses or special contact lenses help, but later treatments such as crosslinking are often necessary to stabilize the cornea. In severe cases, a corneal transplant may be necessary. Early diagnosis is crucial to slow down progression.