A person who has deafblindness can neither see well nor hear well. They are not usually completely without sight or hearing.
Losing, or not having one sense, such as sight or hearing, is challenging enough and people can often use another sense to compensate for the loss of the other, such as learning lip reading. However, communicating with people and getting around is extra difficult when problems with both vision and hearing exist.
Deafblindness can develop in older age, or children can be born with it. Deteriorating vision or hearing may occur at different times and different ages.
The condition is also known as dual sensory loss or multi-sensory impairment.
Deafblindness will be diagnosed based on a person's symptoms, sight and hearing tests.
Treatment for deafblindness will initially concentrate on trying to preserve or boost remaining sight and hearing. This could involve eye operations, or the use of hearing aids for example.
A person living with deafblindness will be offered specialist help to learn to use assistive technology, such as braille, and a guide dog may be recommended to help with a person's independence.
The charity Sense says technology can be a big help for people who are deafblind, including computer equipment that can turn text into braille on a special reader.