Digital screen time has increased as a result of the COVID-19 pandemic. Visual fatigue is a common problem that can arise due to prolonged visual work or exposure to certain environmental factors. The objective measurement of visual fatigue is important for assessing the severity of the problem and developing effective interventions for the same. It is crucial that the visual fatigue level of those who use digital displays is monitored and managed on a regular basis in order to keep their visual fatigue under control. An objective method for measuring visual fatigue that links changes in visual features to changes in visual fatigue has been suggested as a part of this research work. The effect of environmental factors like change in lighting and ambient temperature on visual fatigue has also been studied. Readings from a standard visual fatigue test have been used for the research study. Going further, the proposed method for visual fatigue measurement and the sensor network for monitoring environmental factors can be adapted for integration with wearable devices.