# Effects of Wearing a Swimming Cap and Goggles on Phoria and Fusional Vergence
## 3 Results
### Changes in Phoria and Fusional Vergence  
To compare phorias before and after wearing the swimming equipment rather than the comparison between wearing spectacles and wearing contact lenses, we confirmed initially the mean difference for phorias between wearing (myopia) and non-wearing of soft contact lenses (emmetropia). No statistically significant difference was observed in phoria (Table 2). Changes in phoria and fusional vergence, including NFV and PFV before and after wearing a cap, goggles, and both a cap and goggles for swimming, were analyzed as (1) the difference among means, (2) the frequency based on changes above the coefficient of repeatability or the 95% limits of agreement, and 3) the frequency of prism prescription based on [PERSON]'s criterion. Table 3 shows the difference among the means for phoria and fusional vergence before and after wearing swimming equipment. Phoria is shown as plus for esophoria and minus for exophoria, and fusional vergence is presented as the blur, break, and \begin{table}
\begin{tabular}{c c c} \hline \hline  & **Mean \(\pm\) SD** & **Range** \\ \hline Visual acuity (decimal) & \(1.1\) (1.0–1.2) 1 & 0.8–1.2 \\ \hline Visual acuity (logMAR) & \(-0.04\) \(\pm\) 0.05 & \(-0.08\)–0.10 \\ \hline Myopia after wearing soft contact lenses (\(n\)) & 26 & \\ \hline Phoria at distance (\(\Delta\)) 2 & \(-1.46\)\(\pm\) 3.07 & \(-8.33\)–6.33 \\ \hline Phoria at near (\(\Delta\)) & \(-5.08\)\(\pm\) 6.32 & \(-16.00\)–10.00 \\ \hline Emmetropia after non-wearing of soft contact lenses (\(n\)) & 9 & \\ \hline Phoria at distance (\(\Delta\)) & \(-1.33\)\(\pm\) 2.06 & \(-6.00\)–0.67 \\ \hline Phoria at near (\(\Delta\)) & \(-5.71\)\(\pm\) 5.72 & \(-13.00\)–1.00 \\ \hline \hline \end{tabular} 1  
\end{table} 
Table 1: _Cont._ \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{4}{c}{**Soft Contact Lenses**} \\ \cline{2-4}  & **Wearing (Myopia)** & **Non-Wearing (Emmetropia)** & _p-Value_ \\ \hline Non-wearing of swimming equipment & & & \\ \hline Distance & \(-1.46\)\(\pm\) 3.07 & \(-1.33\)\(\pm\) 2.06 & 0.913 \\ \hline Near & \(-5.08\)\(\pm\) 6.32 & \(-5.71\)\(\pm\) 5.72 & 0.794 \\ \hline Wearing cap & & & \\ \hline Distance & \(-1.13\)\(\pm\) 3.50 & \(-1.19\)\(\pm\) 2.36 & 0.964 \\ \hline Near & \(-4.35\)\(\pm\) 6.50 & \(-4.63\)\(\pm\) 6.28 & 0.913 \\ \hline Wearing goggles & & & \\ \hline Distance & \(-1.49\)\(\pm\) 3.09 & \(-1.41\)\(\pm\) 2.38 & 0.940 \\ \hline Near & \(-4.43\)\(\pm\) 5.34 & \(-5.00\)\(\pm\) 5.95 & 0.789 \\ \hline Wearing cap and goggles & & & \\ \hline Distance & \(-1.45\)\(\pm\) 3.09 & \(-1.17\)\(\pm\) 2.49 & 0.807 \\ \hline Near & \(-4.66\)\(\pm\) 5.37 & \(-5.52\)\(\pm\) 6.89 & 0.703 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Differences in phoria between wearing (myopia) and non-wearing of soft contact lenses (emmetropia). recovery points. Blur points were excluded from the analysis because blur and no blur can coexist. Differences among the means for phoria, NFV, and PFV at distance and at near were not statistically significant (all \(p\) > 0.05, repeated-measures ANOVA). However, NFV at near and PFV at distance and at near while wearing a cap, goggles, or cap and goggles showed suppression in 1-6 cases. Furthermore, when analyzing changes based on non-wearing as a baseline, there were various cases in which an increase, decrease, and no change in phoria or fusional vergence occurred but without showing a definite tendency. Changes were observed in 1050 cases, namely, 84.7% (using cumulative values, 396 cases increased, 449 cases decreased, and 44 cases were suppressed). In 350 cases, the frequency of changes when wearing a cap, goggles, and both a cap and goggles were 86.0% (301 cases), 83.4% (292 cases), and 84.6% (296 cases), respectively. That is, on about four-fifths of occasions, changes in phoria and fusional vergence were a result of wearing the swimming equipment.