**7. Conclusions**

To have complete understanding of existing approaches and identify challenges to be solved as the next step, we conducted a systematic review of 33 papers on touchscreenbased image accessibility for screen reader users. The results revealed that image types other than maps, graphs and geometric shapes such as artwork and comics are rarely studied. Furthermore, we found that only about one-third of the papers provide multimodal feedback of audio and haptic. Moreover, our findings show that ways to collect image descriptions was out of the scope of interest for most studies, suggesting that automatic retrievals of image-related information is one of the bottlenecks for making images accessible on a large scale. Finally, while the majority of studies did not involve people who are blind or have low vision during the system design process, future studies should consider inviting target users early in advance and reflect their comments for making design decisions.

**Author Contributions:** Conceptualization, U.O.; methodology, U.O.; validation, U.O.; formal analysis, H.J. and Y.L.; investigation, U.O., H.J., and Y.L.; data curation, U.O., H.J., and Y.L.; writing— original draft preparation, U.O.; writing—review and editing, U.O.; visualization, U.O.; supervision, U.O.; project administration, U.O.; funding acquisition, U.O. All authors have read and agreed to the published version of the manuscript.

**Funding:** The research was supported by the Science Technology and Humanity Converging Research Program of National Research Foundation of Korea (2018M3C1B6061353).

**Conflicts of Interest:** The authors declare no conflict of interest.
