Modern mirrors (including high-quality mirrors with a front surface) can show small or no gaps, even when they are perfectly normal and safe. Therefore, while the test can be interesting, it shouldn’t be the only method.
Better ways to check a mirror
If you have doubts, here are some practical tips:
1. Check the lighting
Turn off the lights (if possible) and use your phone’s flashlight near the mirror.
A regular mirror reflects light.
If you can clearly see the space or objects behind the glass, this is unusual.
2. Look around.
One-way mirrors only work when:
One side is brightly lit.
The other side is dark.
Ask yourself:
ADVERTISEMENT
