Prismatic Effect, Interpupillary Distance and their Correlation with Stereopsis in an African Population

Purpose This study aims to explore the relationship between interpupillary distance (IPD), prismatic effects and stereopsis in an African population. Methodology A descriptive cross-sectional study was carried out with 96 students aged 18 to 35. Participants were recruited using a non-probability convenience sampling method. IPD was measured using a pupillometer, while stereopsis was assessed with the Randot stereotest. Data were analysed using IBM SPSS Statistics version 27.0.1, with a significance level set at p ≤ 0.05. Results The study included 96 participants: 32 males (33.3%) and 64 females (66.7%), with a mean age of 21.61 (±1.57) years. The age range was 18 to 35. The findings showed that a wider near IPD was associated with poorer stereopsis (p < 0.001). Additionally, introducing prisms in front of the eyes led to a significant reduction in stereopsis (p < 0.001). A significant difference in stereopsis was found between males and females (p = 0.02), with males having a mean stereopsis of 30.16 (±7.01) and females 26.72 (±6.80). There was also a significant difference in near IPD between genders (p < 0.001), with males averaging 64.7 (±3.34) and females 61.5 (±2.06). Conclusion Smaller near IPD is associated with better stereopsis. It also demonstrated that prismatic effects, whether vertical or horizontal, significantly impact local stereopsis, emphasizing the importance of accurate IPD measurement. Females were found to have a smaller IPD and better stereopsis compared to males.