Evaluation of tear volume is important for diagnosing dry eye disease. At the clinical site, dedicated devices such as Slit-lamp Microscopy or Meniscometer have been used to quantify tear volume by ophthalmologist. However, these devices have access only in medical office and therefore have limited availability for the public. Tear volume changes with environmental, physical or psychological situation. For that reason, measurement of tear volume regardless of location, time or circumstances can be beneficial not only for healthcare professionals but also for patients. If tear volume could be measured by using smartphone, it is expected that the smartphone could be utilized as an IoT sensor for the healthcare application. In this study, tear volume measurement system was designed and implemented on smartphone. Further application for smartphone as an IoT device will be discussed.