PURPOSE: Macular diseases often lead to metamorphopsia, which is traditionally tested using the Amsler grid. This study evaluates a novel method for assessing metamorphopsia, based on the software AMD-A Metamorphopsia Detector, application MacuFix®. METHODS: In this observational study, the usability of a new smartphone-based testing method to assess metamorphopsia was evaluated in 45 patients experiencing metamorphopsia in at least one eye using the questionnaire "System Usability Score (SUS)." Additionally, the diagnostic adherence of self-monitoring with the Amsler grid was compared to self-monitoring with the novel software MacuFix®. RESULTS: The average score of the SUS questionnaire in this study was 76.7 ± 15.5, corresponding to the "good" score on the grading scale. The average interval between two home administered tests was significantly shorter (6 days) when the application was used as compared to using the Amsler grid (19 days). The odds ratio of the frequency of patients using the application to the patients using the home test was 4. CONCLUSION: MacuFix® application can help in effective home monitoring of macular function as high user satisfaction and increased testing frequency was observed in its use in patients with macular diseases.