Krause K, Rudolph A
Klin Monbl Augenheilkd. 1985 Jan;186(1):61-5. doi: 10.1055/s-2008-1050877.
Patients with visual acuities of below 0.4 at both long and short range cannot be sure of seeing well enough to read or watch TV. Low-vision aids improve vision to a such a degree that these activities can be performed once again. However, aside from this positive effect, low-vision aids have some disadvantages which sometimes prevent patients from actually using them. An investigation conducted among 150 patients revealed that 84% of them used their low-vision aids for about an hour or so a day.