The purpose of this experiment was to study the role of binocular vision, including both stereopsis and binocular vergence, on the complex task of golf putting. The putting accuracy of 16, visually-normal, inexperienced golfers (range 23-66 years, mean=35 years) was assessed for small (3cm) and large (12cm) targets located at 3, 6, and 9 feet with their distance corrective lenses in place. Subjects performed the task under either normal binocular or monocular viewing conditions. Putting accuracy (% successful putts) was significantly better under binocular versus monocular viewing conditions for the smaller target. This was true for 10 out of 12 (83%, p=0.019), 11 out of 12 (92%, p=0.003), and 12 out of 12 (100%, p<0.001) of the subjects for the 3-, 6-, and 9-foot test distances, respectively. The percentage improvement in putting accuracy under binocular as compared to monocular viewing conditions for the small (3cm) target was 14%, 8%, and 13% for the 3-, 6-, and 9-foot target distances, respectively. For the larger target, the trends were similar but smaller in magnitude (0.5-7%) and not statistically significant. These findings are consistent with earlier studies demonstrating improved athletic performance under binocular versus monocular viewing conditions. The additional depth-related cues provided by stereopsis and binocular vergence appear to be crucial for more precise and detailed tasks, such as were present with the smaller target.
Consecutive exotropia refers to a manifest exodeviation following surgery to correct esotropia. Surgery is common for early onset esotropia, particularly congenital/infantile esotropia. Congenital/infantile esotropia is usually accompanied by several ocular phenomena, including: latent nystagmus, dissociated vertical deviation (DVD) and overaction of the extraocular muscles, especially the inferior obliques. Additionally, since there is a disturbance in normal binocular vision, anomalous correspondence (AC) is often present. Despite this poor or limited binocularity, interventions to increase fusional ability are possible and should be considered.
Intermittent central suppression (ICS) is a repetitive loss of sensation in central vision that occurs in the absence of strabismus and amblyopia. We used electronic rapid alternate occlusion to treat the ICS of 10 students enrolled in a Job Corp�s residential educational program. The location of the program is remote from my office. We performed vectographic examinations on each student to diagnose and classify the ICS. The students also completed a College of Optometrists Quality of Life Questionnaire (QOL) before and after the therapy. The group�s average lessening of frequency of ICS was 76%: The QOL scores tended to improve with the improvement in ICS. The students� and their teachers� subjective responses gave evidence that there were positive changes in reading and performance after the therapy.
In addition to stereopsis, there are several other important benefits to having normal binocular vision. These are reviewed in the context of their functionality, as well as rationale for early detection and intervention of binocular dysfunctions.
The purpose of this study was to evaluate the efficacy of amblyopia therapy utilizing a pair of rotating polarized filters to attenuate the light reaching the non amblyopic eye, and thus reduce its acuity, while still enabling binocular vision. Six amblyopic children between the ages 1 and 6 years were enrolled in the study. They were fitted with glasses that included a pair of polarizing filters in the normal eye and a tinted appropriate optical correction for the amblyopic eye. Three children completed one year's use of the device and they are discussed in this report. In all three cases visual acuity improvement was obtained in the amblyopic eye. In one patient full steropsis was obtained on the Titmus Stereotest. This pilot study indicates that paired polarizing filters may be used as a mode of treatment in amblyopia.
Between January, 1998, and July, 1999, 351 children in foster care placements in New York City received comprehensive vision examinations. One hundred and five of these children also received a hearing evaluation. The children from one of the sites (St. Christopher-Otillie, Brooklyn) were also examined in the audiology department of Brooklyn Hospital. The children were the charge of three different agencies at four sites. The aim of the study was to investigate the visual status of children in foster care placements and whether or not those children with significant visual problems were being identified and followed. Visual acuity, ocular motor function, refractive error, ocular health status, eye vergence skills and stereopsis were evaluated in the vision examinations. Anomalies were rated mild, moderate and severe, newly or previously identified and whether they were likely or not likely to have been present one year earlier (the time of their last physical). In all areas tested, children in foster care had higher prevalences of visual and audiological anomalies, than their normal counterparts. The results indicate that the vision and audiological screenings now being provided to these children at their mandated annual physical examination, are not sufficiently identifying children with moderate or severe vision and audiological dysfunctions.
This paper makes a case for enriching the clinical investigation of stereopsis. A rationale is provided for extending the use of currently available tests to include the speed of attainment in the assessment of stereoacuity both behind and in front of the plane of regard. A research study on a group of university students using these additional parameters on three different stereoacuity tests is described.