The Bug:

The pulsating of the night vision effect isn't accessible-friendly.

When the night vision effect is low in duration, the sky's brightness pulsates, thus in some cases creating a distorting inconvenience for players, especially those who suffer from photosensitive epilepsy.

The in-game additions of the "Hide Lighting Flashes" button and the "Darkness Pulsing" slider heavily suggest that Mojang aims to make the game more accessible to those who suffer from photosensitive epilepsy and other similar problems. This concept is also reinforced by the triaging and fixing of bug reports such as MC-221686, MC-245937, MC-253881, MC-253367, and MC-253968. Additionally, here's a quote from Mojang Studios employee, slicedlime on MC-245937, which further reinforces the same concept as mentioned above.

No photo-sensitivity issues are present in the game

Steps to Reproduce:

1. Set the time to "midnight".

   /time set midnight

2. Give yourself the night vision effect with a low duration.

   /effect give @s minecraft:night_vision 10 0

3. Observe how the sky flashes and how there's no way to stop this from happening, thus potentially harming those who suffer from photosensitive epilepsy and other similar problems.

Observed Behavior:

The pulsating of the night vision effect isn't accessible-friendly and cannot be disabled, thus in some cases creating a distorting inconvenience for players, especially those who suffer from photosensitive epilepsy.

Expected Behavior:

There should be an option to control if or how much the night vision effect can make the sky pulsate.