Deaf-Blindness: Definition & Characteristics

Instructor: Danielle Haak

Danielle has a PhD in Natural Resource Sciences and a MSc in Biological Sciences

The term deaf-blindness is a little misleading, so we're going to spend this lesson learning about what deaf-blindness is, its different causes, and how people with the condition learn to manage it and thrive.

What is Deaf-Blindness?

Janie has deaf-blindness. She had very little hearing from the time she was born, but luckily her parents learned and taught her sign language as soon as she was old enough to comprehend it. They discovered she had a form of Usher Syndrome, so both her hearing and vision would be negatively affected her entire life. Once she turned 14, they realized her vision was gradually getting worse, so she also learned Braille while she still had some sight capabilities left. Janie was scared that both her hearing and her vision were limited, but she felt confident in her ability to communicate, even though her options were fairly limited. This might sound a little scary to someone learning about deaf-blindness for the first time, but Janie's condition is one many people contend with. Let's learn a little more.

The term deaf-blindness is a little misleading. You might be thinking that someone with deaf-blindness is completely deaf and blind. That might be the case, but complete deafness and blindness occurring together is pretty rare.

In terms of this lesson, deaf-blindness is a condition where a person experiences some level of both hearing and vision impairment to an extent that it disrupts their ability to go about life as usual. However, the actual levels of hearing and vision impairment varies with each individual, though they are usually severe enough to disrupt their ability to learn and communicate. Children often require specialized forms of education to meet their needs.

It's estimated that approximately 50,000 people suffer from deaf-blindness in the United States, and about 10,000 of those are children. Deaf-blindness is often related to other physical, medical, or cognitive impairments.

Potential Causes

Just as how the levels of hearing and vision impairment vary by patient, so does the underlying cause resulting in deaf-blindness in the first place.

About half of deaf-blindness cases are caused by Usher Syndrome, a genetic condition where a person is born with some level of hearing impairment, and vision begins to deteriorate later in life. Usually, vision degrades as a result of a condition called retinitis pigmentosa. This is the medical term for a condition that causes the retinas to gradually degenerate with time due to cell death, and the condition is related to Usher Syndrome.

Here is an example of what vision might look like for someone with retinitis pigmentosa.
retinitis pigmentosa

There are three different forms of Usher Syndrome that can lead to deaf-blindness:

  • Type 1: A person is born deaf, and their vision begins deteriorating later in life (usually during their teen years)
  • Type 2: Like Janie, a person is born hard-of-hearing, but not completely deaf, and their vision begins deteriorating later in life (again, usually during their teen years)
  • Type 3: A person is born with normal hearing (or only minor hearing loss), and both hearing and vision begin deteriorating later in life

Though Usher Syndrome is responsible for about half of deaf-blindness cases, there are other causes as well. These can include:

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