According to IDEA, deaf-blindness is officially defined as?

Deaf-blindness, as defined by the Individuals with Disabilities Education Act (IDEA), refers to a unique condition characterized by a concomitant loss of both vision and hearing. This definition indicates that individuals with deaf-blindness experience challenges stemming from both sensory impairments, which significantly affects their ability to communicate, access information, and connect with their environment.

The emphasis on the "concomitant" nature of the loss highlights that it is not simply a case of having one impairment or the other, but rather the combination that leads to distinct educational and developmental needs. This understanding is vital for tailoring appropriate support services and interventions to assist individuals with deaf-blindness effectively.

The other options describe various forms of sensory impairments but do not encapsulate the simultaneous nature of both deafness and blindness required by the IDEA definition. For instance, a loss of hearing with normal vision refers to a singular impairment, while partial hearing with loss of vision does not communicate the necessity of both sensory losses occurring together. Similarly, significant hearing loss with occasional blindness also does not reflect the continuous nature of deaf-blindness as defined by IDEA.