The bright white beams of searchlights suddenly pushed in from all directions.

He felt like the light had actual pressure to it and he used his body to protect Lilith from it.

This was similar to a flash grenade. If a normal person was exposed to this deluge of light, their eyes would be burned, sharp pain would run through their temples, and they might lose all will to fight and just curl up on the spot.

[...]

Hamazura’s vision through the visor was enhanced in a variety of ways, so the powerful light was counteracted and he was given a clear view of the fully-armed Anti-Skill officers crouched low and moving around beyond that curtain. The thick-barreled guns they held in both hands may have been for tear gas grenades.

[...]

Hamazura was not all that surprised thank to the Processor Suit’s visor. The room was now darker than a movie theater, but the visor immediately adjusted its brightness so everything looked the same as it would during midday.

Toaru Majutsu no Index New Testament vol.19