Merge pull request #11484 from KasparoVy/double_down

Re-add The Ability to Natively See in the Dark

code/modules/mob/living/silicon/robot/robot.dm

@@ -1456,4 +1456,4 @@ var/list/robot_verbs_default = list(
 
 	SEND_SIGNAL(src, COMSIG_MOB_UPDATE_SIGHT)
 	sync_lighting_plane_alpha()
-	
+	

code/modules/mob/mob.dm

@@ -1370,5 +1370,19 @@ var/list/slot_equipment_priority = list( \
 /mob/proc/sync_lighting_plane_alpha()
 	if(hud_used)
 		var/obj/screen/plane_master/lighting/L = hud_used.plane_masters["[LIGHTING_PLANE]"]
-		if (L)
+		if(L)
 			L.alpha = lighting_alpha
+
+	sync_nightvision_screen() //Sync up the overlay used for nightvision to the amount of see_in_dark a mob has. This needs to be called everywhere sync_lighting_plane_alpha() is.
+
+/mob/proc/sync_nightvision_screen()
+	var/obj/screen/fullscreen/see_through_darkness/S = screens["see_through_darkness"]
+	if(S)
+		var/suffix = ""
+		switch(see_in_dark)
+			if(3 to 8)
+				suffix = "_[see_in_dark]"
+			if(8 to INFINITY)
+				suffix = "_8"
+
+		S.icon_state = "[initial(S.icon_state)][suffix]"