From The Collaborative International Dictionary of English v.0.48 :
Dim-sighted \Dim"-sight`ed\, a.
Having dim sight; lacking perception. --
Dim"-sight`ed*ness, n.
From WordNet (r) 3.0 (2006) :
dim-sighted
adj 1: having greatly reduced vision [syn: dim-sighted, near-
blind, purblind, sand-blind, visually impaired,
visually challenged]