Development of smart spectacles to monitor and modify myopia-related health behaviour in children

Purpose: To develop a wearable, spectacle-mounted, sensor-based device to monitor and modify myopia risk factors in children, namely near-working distance, light levels and spectral composition.Methods: A wearable, spectacle-mounted device has been developed, which consists of inbuilt sensors, namely: (i) light sensor to detect ambient light intensity; (ii) proximity sensor to measure near-work distance; (iii) microspectrograph to measure spectral power for six visible channels, namely red, green, blue, yellow, orange and violet and (iv) a global positioning system tracker to track the location and the device. The sensors were programmed by Arduino Nano, and the circuit was fixed onto a printed circuit board fitted onto a spectacle frame for pilot testing. Laboratory testing of the prototype was performed using a mannequin. An alert will be set when exceeding the predetermined threshold to help control myopia risk factors.Results: The indoor and outdoor light levels measured using the prototype were less than and greater than 1000 lux, respectively. The actual target distance and the corresponding distance measured by the prototype were highly correlated (R-2 = 0.99). The mean distance measured by the prototype was within 1.5 cm of the actual target distance for distances between 30 and 95 cm. The spectral energy of the indoor location was highest for the orange channel at about 100-160 counts/mu W/cm(2), whereas it was highest for the blue channel in outdoor daylight (10,000-19,000 counts/mu W/cm(2)).Conclusion: A working prototype that can simultaneously measure the viewing distance, light intensity and spectral composition has been developed.