purblind \PUR-blynd\ (adjective) - 1 : Having greatly reduced vision. 2 : Lacking in insight or discernment.
"Even the older children became groping and purblind, and the young saw but dimly, and the children that were born to them never saw at all." - H.G. Wells, 'The Country of the Blind'
Purblind derives from Middle English pur blind, wholly blind, from pur, pure + blind. In time it came to mean something less than wholly blind.