Stereoacuity measurement using a phoropter combined with two 4K smartphones

PURPOSE: To evaluate stereoacuity using a combination of a phoropter and two 4K smartphones. METHODS: A stereopsis measurement system was established using a phoropter (Topcon VT-10) and two Sony 4K smartphones (Sony Xperia Z5 Premium Dual E6883). A total of 154 subjects (69 children and 85 adults) were enrolled for evaluation using this system and subsequent comparison with the Fly Stereo Acuity test. RESULTS: There was a high level of agreement between the two methods using Bland-Altman statistical analysis (children group, 95 per cent limits of agreement ±0.14 log arcseconds [arcsec]; adult group, 95 per cent limits of agreement ±0.13 log arcsec). CONCLUSION: The closely spaced pixels of a 4K smartphone display enable measurement of stereoacuity at a relatively short distance. The flexibility and versatility of the mobile test system are likely to be useful in clinical practice.