I recently received a pack of Night Eagle golf balls for testing. Unlike other glow in the dark balls, the LEDs on these stay on continuously throughout the round. The on-off switch on the ball is activated by shining a light from your smartphone at the sensor (middle ball) for a couple of seconds. To turn it off, you simply shine a light at the sensor again. Ambient light does not turn it off and on.
The light mechanism works well. I’ll let you know in a few weeks how it plays.