Check the screen from direct front view for normal visibility
Move to side angles and verify the display becomes dark or unreadable
Confirm the privacy filter reduces viewing from left and right sides
Test the screen under different lighting conditions
Verify the screen remains clear enough for the intended user at normal viewing distance
Confirm the filter is properly aligned with the display
Check for gaps, bubbles, or misplacement on the screen
Inspect for scratches, cracks, or wear that may reduce effectiveness
Compare visibility with the privacy screen on and off
Confirm the screen does not interfere with touch or input functions
Ensure the privacy effect is consistent across the full display area
Test whether brightness settings affect privacy performance
Verify the screen can be cleaned without damaging the filter
Check that the privacy screen fits the device model correctly
Monitor for signs of reduced effectiveness over time