Darkness fixes

code/modules/mob/dead/observer/observer.dm

@@ -691,7 +691,7 @@ This is the proc mobs get to turn into a ghost. Forked from ghostize due to comp
 		see_invisible = SEE_INVISIBLE_OBSERVER
 
 	updateghostimages()
-	..()
+	. = ..()
 
 /mob/dead/observer/proc/updateghostsight()
 	if(!seedarkness)

code/modules/mob/living/carbon/alien/alien.dm

@@ -5,18 +5,21 @@
 	icon = 'icons/mob/alien.dmi'
 	gender = NEUTER
 	dna = null
-	alien_talk_understand = 1
-	var/nightvision = 1
+	alien_talk_understand = TRUE
+
+	var/nightvision = FALSE
+	see_in_dark = 4
+
 	var/obj/item/card/id/wear_id = null // Fix for station bounced radios -- Skie
-	var/has_fine_manipulation = 0
-	var/move_delay_add = 0 // movement delay to add
+	var/has_fine_manipulation = FALSE
+	var/move_delay_add = FALSE // movement delay to add
 
 	status_flags = CANPARALYSE|CANPUSH
 	var/heal_rate = 5
 
-	var/large = 0
+	var/large = FALSE
 	var/heat_protection = 0.5
-	var/leaping = 0
+	var/leaping = FALSE
 	ventcrawler = 2
 	var/list/alien_organs = list()
 	var/death_message = "lets out a waning guttural screech, green blood bubbling from its maw..."
@@ -153,7 +156,7 @@
 		nightvision = TRUE
 		usr.hud_used.nightvisionicon.icon_state = "nightvision1"
 	else if(nightvision)
-		see_in_dark = 4
+		see_in_dark = initial(see_in_dark)
 		lighting_alpha = initial(lighting_alpha)
 		nightvision = FALSE
 		usr.hud_used.nightvisionicon.icon_state = "nightvision0"
@@ -298,3 +301,6 @@ Des: Removes all infected images from the alien.
 
 	if(see_override)
 		see_invisible = see_override
+
+	sync_lighting_plane_alpha()
+	SEND_SIGNAL(src, COMSIG_MOB_UPDATE_SIGHT)

code/modules/mob/living/carbon/carbon.dm

@@ -1162,4 +1162,6 @@ so that different stomachs can handle things in different ways VB*/
 		lighting_alpha = LIGHTING_PLANE_ALPHA_MOSTLY_INVISIBLE
 
 	if(see_override)
-		see_invisible = see_override
+		see_invisible = see_override
+
+	SEND_SIGNAL(src, COMSIG_MOB_UPDATE_SIGHT)

code/modules/mob/living/carbon/human/human.dm

@@ -551,6 +551,7 @@
 		return
 
 	dna.species.update_sight(src)
+	SEND_SIGNAL(src, COMSIG_MOB_UPDATE_SIGHT)
 
 //Added a safety check in case you want to shock a human mob directly through electrocute_act.
 /mob/living/carbon/human/electrocute_act(shock_damage, obj/source, siemens_coeff = 1, safety = FALSE, override = FALSE, tesla_shock = FALSE, illusion = FALSE, stun = TRUE)

code/modules/mob/living/carbon/human/species/_species.dm

@@ -641,9 +641,6 @@ It'll return null if the organ doesn't correspond, so include null checks when u
 		H.see_invisible = initial(H.see_invisible)
 		H.lighting_alpha = initial(H.lighting_alpha)
 
-	if(H.see_in_dark > 2) //Preliminary see_invisible handling as per set_species() in code\modules\mob\living\carbon\human\human.dm.
-		H.lighting_alpha = min(H.lighting_alpha, LIGHTING_PLANE_ALPHA_MOSTLY_INVISIBLE)
-
 	if(H.client && H.client.eye != H)
 		var/atom/A = H.client.eye
 		if(A.update_remote_sight(H)) //returns 1 if we override all other sight updates.

code/modules/mob/living/living.dm

@@ -1026,3 +1026,5 @@
 	if(stat == DEAD)
 		grant_death_vision()
 		return
+
+	. = ..()

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

@@ -1316,3 +1316,4 @@ var/list/ai_verbs_default = list(
 		see_invisible = see_override
 
 	sync_lighting_plane_alpha()
+	SEND_SIGNAL(src, COMSIG_MOB_UPDATE_SIGHT)

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

@@ -1424,4 +1424,6 @@ var/list/robot_verbs_default = list(
 	if(see_override)
 		see_invisible = see_override
 
-	sync_lighting_plane_alpha()
+	sync_lighting_plane_alpha()
+	SEND_SIGNAL(src, COMSIG_MOB_UPDATE_SIGHT)
+	

code/modules/mob/mob.dm

@@ -1343,6 +1343,7 @@ var/list/slot_equipment_priority = list( \
 	return FALSE
 
 /mob/proc/update_sight()
+	SEND_SIGNAL(src, COMSIG_MOB_UPDATE_SIGHT)
 	sync_lighting_plane_alpha()
 
 /mob/proc/sync_lighting_plane_alpha()