  The majority of blindness is preventable, and is located in developing
countries. While mHealth applications for retinal imaging in combination with
affordable smartphone lens adaptors are a step towards better eye care access,
the expert knowledge and additional hardware needed are often unavailable in
developing countries. Eye screening apps without lens adaptors exist, but we do
not know much about the experience of guiding users to take medical eye images.
Additionally, when an AI based diagnosis is provided, trust plays an important
role in ensuring in the adoption. This work addresses factors that impact the
usability and trustworthiness dimensions of mHealth applications. We present
the design, development and evaluation of EyeGuide, a mobile app that assists
users in taking medical eye images using only their smartphone camera. In a
study (n=28) we observed that users of an interactive tutorial captured images
faster compared to audible tone based guidance. In a second study (n=40) we
found out that providing disease-specific background information was the most
effective factor to increase trustworthiness in the AI based diagnosis.
Application areas of EyeGuide are AI based disease detection and telemedicine
examinations.
