Visual performance improves with practice (perceptual learning). In this study, we sought to determine whether or not adult monkeys reared with early abnormal visual experience improve their stereoacuity by extensive psychophysical training and testing, and if so, whether alterations of neuronal responses in the primary visual cortex (V1) and/or visual area 2 (V2) are involved in such improveme...

PURPOSE A masked investigation of the relation between performance on various vision tests and reading was conducted with 90 kindergartners (mean age 5.73 years) and 91 first graders (mean age 6.76 years) from a middle class, suburban, elementary school near Cleveland, Ohio. METHODS Vision testing included the Modified Clinical Technique (MCT), +/- 2.00 D flipper lenses with red/green suppres...

PURPOSE This study was conducted to identify the relationship between control grade, stereoacuity and surgical success in basic intermittent exotropia. METHODS This retrospective study involved 44 basic intermittent exotropia patients who underwent strabismus surgery and completed at least 6 months of follow-up. The 44 patients were divided into three subgroups according to their control grad...

All pediatric ophthalmologists should be familiar with Dr. Malcom Ing’s classic work on binocularity and stereopsis in children following surgery for infantile esotropia. In this issue, Dr. Ing reports his results of visual and binocular testing performed on patients who had primary implantation of intraocular lenses following the removal of cataracts in their childhood. Monocular and binocular...

Dynamic random dot fusion, stereopsis and stereoacuity were evaluated in 149 healthy, fullterm infants, using both forced-choice preferential looking (FPL) and steady-state visual evoked potential (VEP) protocols. Few infants aged 2-3 months demonstrated fusion or stereopsis in either the FPL or VEP protocol; most infants aged 5 months and older demonstrated fusion and stereopsis in both protoc...

PURPOSE To evaluate the effect of laser in situ keratomileusis (LASIK) on stereoacuity (SA). METHODS This prospective study includes 200 patients scheduled for LASIK. SA was evaluated preoperatively and one week, one month and three months postoperatively using the Random Dot test. Patients with preoperative SA worse than 480 sec/arc were excluded from the study. RESULTS The study included ...

Stereoacuity depends not only on the carrier frequency of Gabor stimuli, but also upon their size. To determine if this is also the case at large disparities, we have measured the upper limit for stereopsis, "Dmax", and assessed its dependence on carrier frequency and overall envelope size. The results differ markedly from the stereoacuity data. Dmax for stereopsis is primarily dependent on the...