In contrast to pervasiveness of computer use and the prevalence of Computer Vision syndrome (CVS) among computer users, CVS is largely unknown to professional computer users, ordinary computer users and even many optometrists.Through this project, we wanted to raise an awareness about CVS, and help computer users monitor their usage data and bring about a behavior change to prevent CVS.
CVS is defined as “the complex of eye and vision problem related to near work which are experienced during or related to computer use”(Yan, Hu, Chen, & Lu, 2008).
We interviewed 12 participants to learn about their computer usage behavior,eye condition, history of eye related problems and also asked for their opinion on preventative measures that could be implemented. Through these interviews we learnt that a majority of them were unaware that their eyes were under strain, and those who had an eye condition, were advised eye exercises, but were so busy with their work that they did not comply with the recommendations from their opthamologist.
The team also interviewed opthamologists and optometrists to get their views on computer vision syndrome, and learnt about standard tests and self reporting methods specifically designed to diagnose CVS.
In general CVS symptoms can be divided into three major categories:
1. Eye-related symptoms: dry eyes, watery eyes, irritated eyes, burning eyes
2. Vision related symptoms: eye strain, eye fatigue, headache, blurred vision, double vision
3. Posture-related symptoms: sore neck, shoulder pain, sore back
The goal of this measurement strategy is to measure the correlation between the factors mentioned above against recommended guidelines in order to aid behavior changes to prevent CVS.
The measurement instrument is a pair of eye glasses that can be worn with anti-glare/prescription lenses, and is connected to a mobile app and also an application running on the work terminal. The key measurement variables are: intensity of light falling on the eye, distance and angle of computing device with respect the horizontal plane, and strain in the eye. On installation of the mobile application, the user will be made to fill a questionnaire based on the Ocular Surface Disease Index (OSDI) self-report. The user will also be asked to upload a photo of something that is important to them or of personal value. Based on the OSDI evaluation, a score will be computed and applied to blur the photo by relative factor that indicates how their vision will be impacted in five years. An application running on the work terminal, periodically captures images of the user’s eye with the help of a web cam. The eye glasses are capable of measuring the intensity of light falling on the eye, lighting in the room, distance between the eye and work terminal, and also head tilt. Based on these measurements, an indicator on the work terminal will provide feedback based on prescribed standards and any deviations that needs correction. The application allows users to enter notes/mental tasks/ questions that they haven’t had the time to think about or find answers. In order to change the behavior to take regular small breaks, users will be asked to perform one of these three tasks every 20 minutes using a prompt on their work station: Look at something 20 feet away for 20 seconds (20/20/20 rule), eye exercises, or think about an item from their list of questions/thoughts. The last measurement is an interval contingent sampling using self-report that measures the user’s perception of vision and eye conditions and is administered using the phone application. The results of these measurements can be viewed on the phone application and also the progression towards healthy vision is represented through the blur factor of the image, sharp image indicated that they are progressing towards their goal.
The eye glasses observe several important parameters in the work environment and provides valid data on duration of computer use, frequency of breaks, posture and lighting conditions. Unlike a book, the computer screen is self-illuminated, constantly refreshes at a certain rate, requires a much higher viewing angel, different resolution affect visual fatigue and readability and the viewing distance is not easily adjusted as compared to simply moving the book by hand to adjust the viewing angle. Lighting conditions are the most important component of the computer rooms that affect visual functioning. Recommended lighting levels are 40-50 FC for ambient light. Research suggests that any luminous source within the computer user’s field of view should not exceed three times the mean screen luminance. Computer users should pace screen at least 20 inches away and should adjust the viewing angle to around 15 degree lower than the lower level to reduce both visual discomfort and musculoskeletal discomfort(Yan et al., 2008). These measurement also indicate when to take a break based on how long they have been using the computer.
One key challenge we had with our current approach of using camera to track eye movement was calibration. We solved* this challenge by tracking mouse movement for different applications. This solution while not very accurate, provided us with enough information through patterns to make a judgement about eye gaze.
This project helped me learn and apply several skills including hardware prototyping, designing a robust measurement strategy and also applying the SWITCH framework by Chip and Dan Heath. Personal informatics is a challenging domain, and if the solution is not well designed, the product could go from kickstarter to the closet within weeks. It is essential to appeal to the rational and the emotional human. I also learnt video recording and editing skills using Final Cut Pro.
I also learnt how to record professional quality videos and edit them using Final Cut Pro.