Why Smart Scroll is not working properly in Samsung Galaxy S4(GT-I9500)?

Smart Scroll in Samsung Galaxy S4 (GT-I9500) uses the front camera to detect your face.You can scroll through webpages and email messages by tilting your head or device while looking at the screen. The response is not instantaneous, possibly because the software needs to figure out what you want to do first. So, there is about 2-3 seconds delay in the response. Smart Scroll will work only when the signal icon turns green.

 Smart Scroll in Samsung Galaxy S4 (GT-I9500)

Smart scroll may not work in these situations :

● When the front camera fails to detect your eyes.

● When the source of light is behind you or when using device in the dark.

● When the device is shaking.

● When interacting with the device in certain ways, such as using palm motions, tapping the screen, hovering your hand above the screen, using multiple windows or pop-ups, etc.