The federal definition of “deaf-blind” is as follows:

“The term deaf-blind means a child who has both auditory and visual impairments, the combination of which causes such severe communication and other developmental and educational problems that he/she cannot be accommodated in special education programs solely for students with hearing impairments, visual impairments, or severe disabilities without supplemental assistance for these dual sensory impairments.” 34CFR300.7(c)(2)

Primary classification of visual impairment includes, but is not limited to the following:

	Totally Blind
	Low vision (visual acuity of 20/70-20/200 in the better eye with correction).
	Legally Blind (visual acuity of 20/200 or less in the better eye with correction)
	Light perception only.
	Documented Functional Vision loss

Primary classification of hearing loss includes, but is not limited to the following:

	Mild (26-40 dB loss)
	Moderate (41-55 dB loss)
	Moderately Severe (56-70 dB loss)
	Severe (71-90 dB loss)
	Profound (91+dB loss)
	Documented Funcational Vision loss

Either or both sensory loss can be diagnosed as being progressive.

Furthermore, if test results of either or both of the senses are inconclusive, individuals may look at the functional impairment caused by the dual sensory loss. If functional impairment warrants, “best practices” and interventions for deafblind individuals may be utilized.

Also consider the following additional criteria when determining if the student should be put on the census of individuals who are deaf-blind; that is, include students who:

• have hearing and vision impairments as demonstrated by accurate vision and hearing tests;
• have vision impairment and diagnosed moderate to severe unilateral hearing impairment (loss of 50dB or greater);
• have vision and hearing impairments of a mild-to-severe degree and additional disabilities;
• have either a vision impairment or a hearing impairment and demonstrate inconsistent or inconclusive responses in an assessment of the other sensory area;
• have multiple disabilities and demonstrate inconclusive responses in both sensory areas during formal evaluation and/or in educational settings;
• have either a vision impairment or hearing impairment and have a degenerative disease or pathology that affects the acuity of the other sensory area, e.g. Usher syndrome; or,
• have been diagnosed as having a condition that impacts both hearing and vision such as CHARGE syndrome

In addition, children birth to two who are experiencing developmental delays in vision and hearing are also eligible to be included on the census.

Generally speaking there are four categories of individuals who are deaf-blind:

	Congenitally deaf-blind: Individuals who are born with dual visual and hearing loss or experience sensory loss early in the developmental period.
	Adventitiously deaf-blind: Individuals experience dual sensory loss later in life and may not have occurred at the same time.
	Congenitally deaf and adventitiously blind: These individuals experience hearing loss at birth or soon after and experience loss of vision later in life.
	Congenitally blind and adventitiously deaf: These individuals experience vision loss at birth or soon after and experience loss of hearing later in life.