TACTILE ACUITY, AGING, AND BRAILLE READING IN LONG-TERM BLINDNESS

Tactile acuity came under investigation in 69 blind and 69 age-matched , sighted adults. Measures comprised thresholds for discriminating gap s, length (lines), and orientation (along vs. across the finger). Acui ty of blind and sighted participants' index fingertip declined as a fu nction of age at the same rate: roughly 1% threshold rise per annum. S lower braille reading paralleled this decline, as assessed with a tact ile adaptation of the Tinker-Carver test. From youths to elders, howev er, blind participants outperformed sighted participants with the fing ertip but not the lip, a site of commensurate acuity. Experimental tri als of enlarged braille and development of a tactile Snellen-type char t for screening of acuity-related difficulty suggest themselves as pro mising applications.