Wiktionary
deafblindness
n. The medical condition of being both deaf and blind.
Wikipedia
Deafblindness
Deaf-blindness is the condition of little or no useful sight and little or no useful hearing. Educationally, individuals are considered to be deaf-blind when the combination of their hearing and sight loss causes such severe communication and other developmental and educational needs that they require significant and unique adaptations in their educational programs. Helen Keller was one such individual.