For purposes of this chapter—
(1)
the terms “Helen Keller National Center for Youths and Adults who are Deaf-Blind” and “Center” mean the Helen Keller National Center for Youths and Adults who are Deaf-Blind, and its affiliated network, operated pursuant to this chapter;
(2) the term “individual who is deaf-blind” means any individual—
(A)
(i)
who has a central visual acuity of 20/200 or less in the better eye with corrective lenses, or a field defect such that the peripheral diameter of visual field subtends an angular distance no greater than 20 degrees, or a progressive visual loss having a prognosis leading to one or both these conditions;
(B)
who despite the inability to be measured accurately for hearing and vision loss due to cognitive or behavioral constraints, or both, can be determined through functional and performance assessment to have severe hearing and visual disabilities that cause extreme difficulty in attaining independence in daily life activities, achieving psychosocial adjustment, or obtaining vocational objectives; or
(Pub. L. 98–221, title II, § 206, Feb. 22, 1984, 98 Stat. 34; Pub. L. 102–569, title IX, §§ 905, 908(c)(1), Oct. 29, 1992, 106 Stat. 4482, 4486.)