Understanding Vision

What is a visual impairment?

Older people aren’t the only ones affected by vision problems. This article discusses what helps the visually impaired, offering them flexibility and pleasure in life

17 October 2021

Many of us wear glasses or contact lenses; it is thanks to these visual aids that we can see normally again. But what to do when this is not sufficient? Any human being can, at any time, be afflicted by a visual impediment. However, visual impairments are especially common in old age. In this article we show what the reasons may be and how both increased visual aids and the people around them can help those affected.

There is a wide range of different visual impairments which, to a certain extent, are often not recognizable at all by an observer. Close relatives, work colleagues or friends cannot imagine some of the everyday difficulties faced by someone who is suffering from a visual impairment. However, there are many small things that will improve the lives of those affected, in particular, their level of independence and capacity to live and work with others.

Every visual impairment has its own individual characteristics and patients report a variety of symptoms: restricted visual field (tubular vision field), visual field loss, sensitivity to blinding light, nocturnal blindness, colour blindness or general stark limitation of visual capability. Even among similar diagnoses, the effects can be very different from person to person.

Visual capabilities as defined by social legislation: This is classified by the level of the impairment, using percentages. It dictates which support can be imparted in which stages of development. If, for example, a person can recognize a particular object from a distance of 4 inches that a normal person could see from a distance of 328 feet, then for this person the applicable percentage is 10% rather than 100% (Vision = Visual Acuity = 0,1).

A decisive factor for the classification of a particular visual impairment, besides the visual acuity factor, is the extent of the field of vision. So there are the following three different kinds of visual impairment:

Physically present impairment: glasses improve visual acuity (far sight and near sight) by no more than 30% (Vision 0.3); there is an appropriately graded visual capacity distortion (normally damage to one’s field of vision).
High-grade visual impairment: glasses improve visual acuity (far sight and near sight) by no more than 5% (Vision 0.05); with higher-grade visual impairments, there are further visual capacity distortions (normally restrictions to one’s field of vision).
Blindness as defined by the law: glasses improve visual acuity (far sight and near sight) by no more than 2% (Vision 0.02); one’s visual capacity is so strongly disrupted by restrictions to one’s field of vision that the resultant limitation of a visual acuity reduction is equivalent to 2%.

This is a term that describes a group of inherited diseases, the effects of which include destruction of the retina and destruction of the tissue capable of vision at the back of the eye. Despite intensive research work, this disease remains untreatable. Typically it causes impaired vision in half-light and nocturnal blindness, field of vision restrictions and loss, and disruptions to colour and contrast vision and blend sensitivity. The process usually happens gradually and insidiously, over a time span measured in decades.
In a case of macular degeneration (MD), the patient’s retina degenerates (i.e. decays). At the time of writing there is no sure therapy for any form of this disease. Magnifying visual aids (like magnification glasses or telescopic spectacles) are important means of assistance for those affected. In every case, regular testing by an eye care professional is necessary. Especially important is the protection against UV radiation with a good pair of sunglasses. Some people suffer from age related macular degeneration – this appears ever more frequently in parallel with longer life expectancy. The exact causes have not yet been clearly defined. Metabolism changes in specific retina layers, as well as increasing deposits in the retina membrane (underneath the retina) that come with old age are thought to play a role.
This begins with a case of hearing damage that one is born with (hearing difficulties or deafness), supplemented by an increasing visual impairment at a later stage. Here also, we are talking about retinitis pigmentosa, or retina degeneration.

There are countless ways to help people with visual impairments

Magnifying visual aids: There is a range of visual aids that can be used, depending on the grade of the visual impairment. They can be ordered from an eye care professional and fitted with additional optical devices. In every case, it is important to have an individual customization of the visual aids for the particular person who will be wearing them. Only this way can an optimal visual performance for every individual person affected be achieved. This recognizes the need for best possible reproduction quality in combination with a field of vision that is as large as possible.
Because visual impairments are not always equally easily identifiable from the outside and cannot always be measured with equal accuracy, as well as having very different symptoms, always be ready to help when you are asked. Pay special attention to individuals with visual impairments who are moving around in public while not using a guidance stick. They might ask for information such as the destination displayed on a bus sign, a traffic light button or a reservation place number. A clear and unambiguous answer will be very helpful. Don’t be taken aback if you see someone carrying a blind person’s stick in their hand buying a magazine at a kiosk or reading a book on a train with the aid of a magnifying glass. They are not malingerers. It is also possible that those affected can orient themselves in their everyday lives and that they may only be hampered at night to the extent that they need to use a guidance stick. Thanks to everyday mobility training, many people with visual impairments do get around very well – only in specific cases do they require any support.
Contrasts help! Contrasts help! It makes sense to layout rooms, pieces of furniture or even the settings on the dinner table so that they are more compatible with the needs of a visually impaired person whose orientation is restricted. Even and dazzle-free lighting will also help. Additional lamps, which can be easily used to aid reading or kitchen work, also represent good support tools. The best choice: Cold light sources with high light intensity. Halogen lamps are less suitable.
Normally, those who are visually impaired have a tough time writing notes by hand. It helps to ask them to print the characters on white paper using a thick black pen.
Whenever you are talking face to face to someone who is visually impaired, don’t be surprised or confused if your counterpart fails to make direct eye contact with you. There may be times where, as a result of the impairment of the central field of vision, someone suffering from it may give you the impression that he / she is looking at a point beyond you. Just continue to have a normal conversation. Sometimes those who are visually impaired can be incorrectly labelled as arrogant and impolite. But don’t forget that many situations that are completely normal for you take extreme concentration for a visually impaired person and that can it can often cost them a lot of effort. Moreover, many people who are struggling with visual impairments caused by ever increasing loss of visual acuity are unable to recognise faces, and especially gestures of other people altogether (or they can only do so at a very close range). So when you greet someone who has this impairment, you may not even receive a response.

A tip for gift giving: For relaxation and entertainment, many visually impaired people thoroughly enjoy audio books, now available in either CD format or as an Internet download.