The Smart Stay feature on your Samsung Galaxy S3 is made to ensure that the screen does not turn off, when you are looking at it. You can turn on this feature by going to Settings – Display. The Smart Stay feature works by virtue of the front-facing camera which checks if you are looking at the screen. You can also see the eye-icon pop up in the notification bar. The S3 will check how much time you look at the screen depending on the ‘Screen Timeout’ setting feature. If you find that Smart Stay feature does not work, here are things that you can do –
1. Ensure that you are on a background which has enough light so that the front facing camera can see you. If you are in the shadow or there is too much darkness, the screen will time out.
2. Make changes in the ‘Screen Timeout’ section if it does not turn off fast enough
3. Check the front-facing camera if it is working properly.