A comparison of contrast letter thresholds in unilateral eye enucleated subjects and binocular and monocular control subjects

We previously reported that unilaterally eye enucleated subjects show superior contrast letter acuity to normally sighted monocular viewing control subjects. We suggested that reorganization of the visual system in the enucleated subjects may compensate for their loss of binocularity. Here we measured contrast letter acuity in normally sighted binocular control subjects and compared these results to previously published results of eye enucleated subjects and monocular viewing control subjects. We found equivalent performance between enucleated subjects and binocular control subjects, suggesting that performance of enucleated subjects might be due to some form of neural summation.