These results are not presented here because they support what has already been reported in the literature--that magnification improves near acuity
and the performance of activities of daily living.
Results from the factor analysis performed on the experiences while driving questions revealed that both low-vision and nonimpaired drivers reported visual difficulties in six areas: near acuity
(with emphasis on night driving), peripheral vision, glare (with emphasis on night driving), visual obstruction, motion perception, and distance acuity.
05 LogCS (noticeable loss or normal threshold, that is the threshold somewhere on the lower four lines of a Pelli-Robson chart) are likely to do well, and only those with poor baseline near acuity
and a CS on the top four lines of a Pelli-Robson chart (severe or significant loss) unlikely to read 1M print with magnification.
A measurement of near acuity
should be paramount, along with recording accommodation, in determining when to prescribe.
In the UK, near acuity
is usually assessed by a reading task and the result recorded by print size.
The above method describes the minimum magnification required to view a high contrast near acuity
test card, of pre-determined size.
This rule gives an estimation of near acuity
based on the distance acuity.