Vision

What Is Visual Impairment?

Not only older people are affected – what helps the visually impaired and gives them flexibility and joy of life.

Many of us wear glasses or contact lenses and can see normally again thanks to these visual aids. But what if this is not enough? Everyone can be affected by a visual impairment at any time.

However, visual impairments occur particularly frequently in old age. Here we show what can be behind it and how both magnifying vision aids and each of us can help those affected.

There are a multitude of different visual impairments, some of which are often not recognised by outsiders at first glance. Even for close relatives, colleagues at work or friends, some everyday difficulties resulting from the visual impairment cannot be assessed. However, many small things can make life, independence and togetherness easier for those affected.

Every visual impairment is very individual and has a variety of effects: Restriction of the visual field (tubular visual field), loss of visual field, sensitivity to glare, night blindness, colour vision impairment or general severe visual impairment. Even with similar diagnoses, the effects can be very different for those affected.

Vision according to social law: In Germany this is classified by the degree of disability (GdB) according to percentage. This regulates what kind of support can be claimed and to what extent. If, for example, a person can see a certain object from a distance of 10 metres, which a person with normal vision can already see from a distance of 100 metres, this person sees only 10% instead of 100% (visual acuity = 0.1).

In addition to visual acuity, the extent of the visual field is also decisive for the classification of the disability. Thus the following three visual impairments are distinguished:

Physically significant disability: With glasses, the visual acuity of the better eye in the distance and near is not more than 30% (visual acuity 0.3), or there is a disturbance of vision of corresponding severity (usually visual field damage).

High degree of visual impairment: With glasses, the visual acuity of the better eye in the distance and near is not more than 5% (visual acuity 0.05), or in the case of higher visual acuities of the better eye there are further visual acuity disorders (usually visual field restrictions).

Blindness in the sense of the law: With glasses, the visual acuity of the better eye in the distance and near is not more than 2% (visual acuity 0.02) or the visual acuity is so strongly disturbed, for example by visual field restrictions, that the resulting impairment of visual acuity equals a reduction of 2%.

What causes visual impairment?

Often visual impairments are caused by degenerative diseases of the retina of the eye:

Retinitis pigmentosa (RP): Retinitis pigmentosa is the name given to a group of hereditary diseases that result in the destruction of the retina, the tissue at the back of the eye that is capable of seeing. Despite intensive research, this disease is still incurable. Typical symptoms are disturbed twilight vision and night blindness, narrowing and loss of the visual field, disturbances in colour and contrast vision and sensitivity to glare. The process usually takes decades.

Macular degeneration (MD): In macular degeneration, the patient’s retina degenerates (i.e. destroys). A reliable therapy is not possible for any form of this disease. Magnifying vision aids, such as magnifying glasses or telescope glasses, are important aids for the affected persons. Regular ophthalmological check-ups are always necessary.

In particular, protection against UV radiation by good sunglasses is important. AMD (age-related muscular degeneration) is becoming increasingly common due to the longer life expectancy that we now have. The exact causes have not yet been clarified. Metabolic disorders in certain retinal layers as well as increasing deposits in the tissue membrane below the retina with age are said to play a role.

Usher syndrome: Usher syndrome begins with congenital hearing loss (hearing loss or deafness), to which increasing visual impairment is added later. This is also retinitis pigmentosa, i.e. retinal degeneration.

There are many ways to help people with visual impairment

Visual aids: Depending on the degree of visual impairment, different visual aids are used. They can be prescribed by an ophthalmologist and adjusted by an optician. In any case, it is important to adapt the visual aid individually to the wearer. This is the only way to achieve the optimum visual performance for each individual patient. This includes the best possible imaging quality with the largest possible field of vision at the same time.
Since visual impairments cannot always be recognised or correctly assessed by outsiders and have very different effects, it is important to help in every case when one is approached.

Even if a visually impaired person is travelling without a cane or yellow armband and asks for information such as bus inscription, traffic light or seat number of a reservation, a clear and unambiguous answer will help. So don’t be taken aback when a passer-by with a cane in her hand buys a magazine at a kiosk or reads it in the train with a magnifying glass. She is not a simulator.

Thus it is also possible that concerning can orient itself on the day and are dependent only at night on the blind stick. Thanks to mobile training, many visually impaired people can move very well in everyday life and only need support in certain cases.