If a token is selected that has "Has Sight" it'd be nice to have a toggle to make it so the GM can see only what that token sees, i.e. one of their own or when using Roll20 at home, one account as the GM and another for all of the players at the table on another monitor like I do at my home games. This would allow each player to see only what their character sees, the catch is that there would need to be a darkvision distance as well, which when sight activision takes place that is applied to the "light source" while others no longer selected would remove their darkvision distance, if applicable, taking into account actual light sources that all players can see.