Are there any risks or potential issues for users?

Using light to measure physiology has become more and more common, it's everywhere from smartwatches to sleep trackers. 

There are widely accepted standards for how much light is safe [IEC 60825, ANSI Z136], and we follow these standards in our product.

We are registered as a Class 1 Laser Device with the United States Food and Drug Administration Center for Devices and Radiological Health (US FDA CDRH).