Visual impairment is when a person has sight loss that cannot be corrected using glasses or contact lenses.

There are two main categories of visual impairment:

• being partially sighted or sight impaired – where the level of sight loss is moderate
• severe sight impairment (blindness) – where the level of sight loss is so severe that activities that rely on eyesight become impossible

How vision is measured

There are two main areas that are looked at when someone's vision is measured:

• visual acuity – which is your central vision and is used to look at objects in detail, such as reading a book or watching television
• visual field – which is your ability to see around the edge of your vision while looking straight ahead

The Snellen test

A Snellen test measures your visual acuity. It involves reading letters off a chart on which the letters become progressively smaller. This chart is used during a routine eye test.

After the test you are given a score made up of two numbers. The first number represents how far away from the chart you were able to successfully read the letters on the chart. The second number represents how far away a person with healthy vision should be able to read the chart.

So if you were given a visual acuity score of 6/60, it means you can only read 6 metres away what a person with healthy eyesight can read 60 metres away.

Visual field testing

During visual field testing you will be instructed to look straight ahead at a device while lights are flashed on and off in your peripheral vision. You will be asked to press a button every time you see a light. This shows any gaps in your field of vision.

Partial sight

Partial sight, or sight impairment, is usually defined as:

• having very poor visual acuity (3/60 to 6/60) but having a full field of vision, or
• having a combination of moderate visual acuity (up to 6/24) and a reduced field of vision or having blurriness or cloudiness in your central vision, or
• having relatively good visual acuity (up to 6/18) but a lot of your field of vision is missing

Severe sight impairment (blindness)

The legal definition of severe sight impairment (blindness) is when ‘a person is so blind that they cannot do any work for which eyesight is essential’.

This usually falls into one of three categories:

• having extremely poor visual acuity (less than 3/60) but having a full field of vision
• having poor visual acuity (between 3/60 and 6/60) and a severe reduction in your field of vision
• having average visual acuity (6/60 or better) and an extremely reduced field of vision

Getting help

There are support services, charities and devices that can all help make life easier if your vision is impaired.

Just because you have low vision, it does not mean you are no longer able to work. With the help of assistive technology, training and support, many people who are either partially sighted or blind can continue to work in often very demanding roles. Probably the most well known example is the politician David Blunkett.

Read more about getting help and support if you are living with a visual impairment.

Registering as visually impaired

It is also important that you register as visually impaired. To register, your visual acuity and visual field will have to be tested by an ophthalmologist (a doctor who specialises in treating eye conditions).

If the results show you are partially sighted or blind, you will be issued with what is known as a Certificate of Visual Impairment (CVI) and a copy will also be sent to your local social services.

Being registered as visually impaired can entitle you to a range of benefits, such as:

• Disability Living Allowance (DLA) – a tax-free benefit to help with any costs a person has relating to their disability
• a 50% reduction in the TV licence fee
• tax allowance
• a disabled person’s card

Your GP or ophthalmologist can provide more information on registration.

Driving

If you are diagnosed with a condition known to cause low vision, you have a legal obligation to inform the Driver and Vehicle Licensing Agency (DVLA). Failure to do so is a crime and can result in a £1,000 fine.

The Directgov website has advice about how to tell the DVLA about a medical condition.

If you are registered as having a sight impairment or a severe sight impairment, the DVLA will assume that your driving licence is no longer valid and you will no longer be able to drive.

Occasionally, exceptions are made in people with mild sight impairment. If you think this applies to you, then your doctor will need to fill in a questionnaire for the DVLA (PDF, 266Kb).

You are only legally allowed to drive if you can read a number plate from a distance of 20 metres (65 feet). You are allowed to wear glasses or contact lenses when reading the plate.

Who is affected

There are around 360,000 people who are registered as visually impaired in England. As many as 2 million people in the UK may be living with some degree of visual impairment.

Most cases of visual impairment in this country are caused by ageing. It is estimated that around 1 in 5 people over the age of 75 have some degree of visual impairment.

Some of the most common causes of visual impairment include:

• age-related macular degeneration (AMD) – where the central part of the back of the eye (the macular, which plays an important role in central vision) stops working properly
• cataracts – where cloudy patches can form on the lenses of the eyes
• glaucoma – where fluid builds up inside the eye, damaging the optic nerve (which relays information from the eye to the brain)
• diabetic retinopathy – where blood vessels that supply the eye become damaged due to a build-up of glucose

Can vision be restored?

It depends on the underlying cause.

Cataracts can be treated with surgery that usually leads to at least a partial improvement in vision. Read more about cataract surgery.

In cases of AMD, glaucoma and diabetic retinopathy, it is usually not possible to restore vision. However, there are several treatments that can prevent further damage to vision, or at least slow down the progression of these conditions.

Read more about treating AMD, treating glaucoma and treating diabetic retinopathy.

Being told you have a visual impairment or you are going to be visually impaired in the future can have a tremendous emotional impact.

Many people have reported going through a process much like bereavement, where they experience the following emotions:

• shock and numbness – ‘it was like I was in a daze and nothing was real’
• anger – ‘I remember thinking “why me, I don’t deserve this”. I was furious’
• denial – ‘I felt sure there was nothing wrong with my eyes and the doctors had made a mistake’
• fear and anxiety – ‘I felt so scared of the future, knowing my sight was going to get worse’
• sadness and grief – ‘I just sat in my room for hours crying and crying’
• acceptance – ‘I started planning how I was going to live with a visual impairment and I started feeling more optimistic about the future’

Most people come to terms with their visual impairment, but in some people the diagnosis can trigger depression, especially in the first few months.

You may be depressed if during the past month you have been very down and felt hopeless, and you no longer take pleasure in activities you used to enjoy.

If you are concerned that you may be depressed, you should contact your GP as there are several treatments that are usually effective for most people, such as cognitive behavioural therapy and antidepressant medication. Read more about treating depression.

Support groups

Probably the most useful thing you can do after being diagnosed with visual impairment is to contact a support group for people with sight loss.

Royal National Institute of Blind People

The UK’s leading charity for people with visual impairment is the Royal National Institute of Blind People (RNIB).

The RNIB operates a helpline for people affected by visual impairment. The helpline is open from Monday to Friday from 8.45am to 5.30pm on 0303 123 9999. You can also email helpline staff at helpline@rnib.org.uk.

The RNIB's website is specially designed for people with a visual impairment and provides a wide range of useful information and resources, and an online community.

The site also has an online shop that sells different products specially designed for people with a visual impairment.

Action for Blind People

Another useful organisation is Action for Blind People, a national charity that provides practical help and support for visually impaired people.

It’s particularly useful for advising on the day-to-day practicalities of living with a visual impairment, such as making adjustments to your home to make it easier to get around, and advice on employment.

Social services

It is recommended that you contact your local social services department to inform them that you have been diagnosed as having a visual impairment.

You may be entitled to a range of benefits as well as practical support, such as help with housework and cooking meals.

The directgov website has a list of all councils and local authorities in England.

Changes to your home

Most people with a visual impairment can continue to live at home. However, you will probably need to make some changes to your home, especially if you live by yourself.

There are several important pieces of equipment you should consider buying:

• Big-button telephone – both landline and mobile models are available from the RNIB online shop.
• Computer – the internet can provide a real sense of connection to friends and family as well as other people with a visual impairment. It is also a practical way of finding out information and obtaining goods and services. Big-button keyboards, screen display software and text readers are available from the RNIB.
• Community alarm – this small wearable device has an alarm button. If pressed it sends an alarm signal to a response centre, which will alert a nominated friend or carer. Your local authority should be able to provide you with more information.
• Bright lighting – bright light bulbs and adjustable lights are essential for your home, especially in the kitchen and the stairs (areas where you are most likely to have an accident). Fluorescent bulbs are recommended, as these produce the most light and tend to be cheaper in the long term than conventional bulbs.

The way your house is painted can also make it easier to find your way around. Using a two-tone contrast approach, such as black and white, can make it easier to tell the difference between nearby objects, such as a door and its handle or the stairs and its handrail.

Travel

Long cane

Many people who are visually impaired find it useful to use a long cane when travelling.

This is a long, usually foldable cane that can help you get around by detecting objects in your path. It also lets drivers and other pedestrians know that you have a visual impairment.

To get the most use out of a cane, you will need to attend a training course in how to use it. The RNIB helpline can provide more details on training.

Guide dogs

The charity Guide Dogs (formerly known as Guide Dogs for the Blind) has been providing guide dogs to people with visual impairment for many years.

Guide dogs are trained to guide their owner in a straight line until instructed otherwise, stopping at obstacles along the way.

Over time, a guide dog can learn regular routes, such as your visit to the supermarket or local train station.

However, guide dogs will not resolve all problems associated with travel and it can take months of careful training before they can be used to their best ability. Also, not everyone with a visual impairment is suitable for using a guide dog.

Many people with a visual impairment find that a guide dog can bring them both independence and companionship.

You can apply for a guide dog using the following online form or by phoning 0845 3727499. You will be charged a fee of 50p.

You will be asked to pay for any vet fees and, if possible, make a contribution towards the cost of dog food. If you are on a low income, the charity may be able to meet these costs.

Global positioning system

A global positioning system (GPS) is a navigational aid that uses signals from satellites to provide a real-time update on a user’s current geographical location.

GPSs are available as stand-alone units that can be programmed using a Braille keyboard (see below), which then provides both a visual map and a voice prompt of your current location.

Alternatively, you can download a number of GPS apps to your smartphone.

However, it is important to note that GPSs will usually only work if you are outdoors.

The RNIB has more information on how GPS can help people with visual impairment.

Reading and writing

If you are having problems reading standard texts in books, newspapers and magazines, there are several options available.

E-readers are handheld devices that allow you to download books and subscribe to newspapers and magazines on the internet. You can then set the device to display text at a larger size.

The RNIB also has a collection of large print publications that you can borrow, as do most libraries.

If you are unable to read at all, you could:

• sign up to the National Talking Newspapers and Magazines scheme, which can provide audio versions of over 250 titles by email or on CD
• sign up to the RNIB Talking Books Service, which can send you audio books to listen to on your computer or on a free device known as a DAISY player

You can also install screen-reading software on your computer that will read out emails, documents and text on the internet.

A charity called Communication for Blind and Disabled People has released a free screen reader for the PC called Thunder. Download the screen reader.

Similar software is available for Apple devices, although you may have to pay a small fee.

There are also voice recognition programmes where you speak into a microphone and the software translates what you say into written language.

You can also use the software to issue commands such as closing browser windows and moving from one website to another.

Braille

Some people who are severely sight impaired choose to learn Braille. Braille is a writing system where raised dots are used as a substitute for written letters.

As well as Braille versions of books and magazines, you can buy Braille display units, which can be attached to computers so you can read the text of a computer screen.

Braille keyboards are also available, so you can use Braille as a writing system.

The RNIB has more details about reading and writing and how you can become trained in using Braille.

Employment

If you are currently employed and have recently been diagnosed with a visual impairment, you should contact the Access to Work scheme.

Access to Work is a scheme run by Jobcentre Plus that provides advice and support on what adjustments and equipment may be required to enable you to do your job.

They also offer a grant to contribute towards the costs of any equipment or training that you may need, such as voice recognition software, a Braille keyboard and display unit and a printer that can covert text into Braille (Braille embossers).

Depending on the size of the company you work for, the grant can pay for 80-100% of costs, up to £10,000.

The directgov website has more information on Access to Work.

If you are currently looking for work, there are three main organisations that can provide some extra advice and support:

• the RNIB, which has a useful section on their website about looking for work
• Jobcentre Plus 
• Action for Blind People

You do not have to disclose that you are visually impaired when applying for a job, but it is usually recommended that you do.

If you feel you have been turned down for a job because of your disability, and you were capable of doing the job, you can make a complaint under the Equality Act 2010. Visit the Home Office website for information on how to do this.

Some people with a visual impairment decide to become self-employed, often because it allows them the flexibility to work at home for the hours they choose.

Action for Blind People has self-employment advisers who can provide information and training on issues such as drawing up a business plan, obtaining funding and bookkeeping. Read more about self-employment on the Action for Blind People’s website.