A successful reading aid is defined for this study as one which the patient uses to read books, magazines, or newspapers for at least 15 minutes at a time. The aid is considered a partial success if the reading time is less, or if only larger print can be read.
A low incidence of failure was found in 513 unselected patients. Occasional failures were associated with a changing level of visual impairment, or a very small usable field of vision. The majority of those not helped with a reading aid either required high magnification, or were of advanced age, or both. Even of those with a poor prognosis, ie, over 70 with reading vision at 40 cm of 10M or worse, 48% were nevertheless helped by a reading aid.
Sloan LL. Reading Aids for the Partially SightedFactors Which Determine Success or Failure. Arch Ophthalmol. 1968;80(1):35-38. doi:10.1001/archopht.1968.00980050037005