# User Friendliness of a Wearable Visual Behavior Monitor for Cataract and Refractive Surgery
###### Abstract
[18] developed a Patient-Reported Spectacle Independence Questionnaire (PRSIQ) to assess spectacle independence following cataract surgery. The questionnaire was developed using conventional qualitative and modern measurement theory methods, and evidence was garnered for the use of PRSIQ as a measure of spectacle independence. While the use of questionnaires and visual assessments in measuring patient outcomes are effective, there are limitations regarding the subjectivity of the results. Current psychometric measures may be subject to systematic error such as recall bias and could cause judgment errors resulting in patient discontentment with surgical outcomes [19; 20]. Visual information based on patient behavior can be harnessed using technological tools that perform eye tracking, analyzing visual behavior under various circumstances. Eye tracking technologies can be used to attain and process objective information of a patient's everyday activities, crucial for selecting an appropriate IOL. Integrating technology that collects objective visual behavior data into pre-operative patient assessments has shown to improve the current understanding of patient behavioral gaze. The data generated could aid clinicians to provide a highly individual evaluation of a patient's visual needs, including distance estimates of the patient's sight, and determine the right course of action to improve post-operative patient outcomes and patient satisfaction. To date, most approaches have focused on diagnostic testing in a clinical setting. In-clinic measurements cannot fully replicate a patient's daily visual needs. The Visual Behavior Monitor (VBM, Vivor AG, Zurich, Switzerland) is a wearable device to be attached on the spectacles of a patient and perform continuous measurements as he or she goes about their daily activities. The challenge of unassisted monitoring in outpatient settings is ensuring correct use of the monitoring system and reliability of the data. This is especially the case for the senior cataract patients with compromised visual function due to age-related cataract and/or presbyopia. While aiming to develop a compact and non-obtrusive system, it is essential to ensure that the reduced form-factor of the device does not impede the handling of the device by the elderly population. Another challenge is to design the user interfaces of the system in a way that can be correctly interpreted by patients with different levels of exposure to computer and information technologies. Most of the recent progress in the information technologies has been pushed forward generally by the young generations of earlier adopters and, thus, interfaces are shaped for and by this population group, who have enough time and interest to work with new technologies. It is critically important to redesign the user experience from scratch with wearable systems for all population groups. Inadequately designed systems ignoring the specifics of the population groups might not only be inefficient in delivering required objective information, but also lead to reduced patient satisfaction due to frustration from handling the device. This is aggravated by the patient awareness that the outcome of the surgery might depend on his or her ability to handle the system. With all the above in mind, the system should be comfortable for use by the patients of various age groups, educational backgrounds with different levels of exposure to information technology, and possibly with compromised vision. The present study was initiated to understand the feasibility of the non-intrusive monitoring of visual behavior and VBM handling by, particularly, a cataract-age population without supervision of a healthcare professional (HCP). The study is designed to evaluate the ease of use, as well as patient perception of wearing the device. This can potentially answer the question of whether patients are willing to use and able to handle the wearable device mounted on the spectacles and are comfortable to use it in order to perform the required measurements.