diff --git a/code/__HELPERS/icons.dm b/code/__HELPERS/icons.dm
index ed4f3242c4d..0b37872decd 100644
--- a/code/__HELPERS/icons.dm
+++ b/code/__HELPERS/icons.dm
@@ -948,10 +948,16 @@ The _flatIcons list is a cache for generated icon files.
 	return "#[color]"
 
 //Imagine removing pixels from the main icon that are covered by pixels from the mask icon.
-/proc/get_icon_difference(var/icon/main, var/icon/mask)
+//Standard behaviour is to cut pixels from the main icon that are covered by pixels from the mask icon unless passed mask_ready, see below.
+/proc/get_icon_difference(var/icon/main, var/icon/mask, var/mask_ready)
+	/*You should skip prep if the mask is already sprited properly. This significantly improves performance by eliminating most of the realtime icon work.
+	e.g. A 'ready' mask is a mask where the part you want cut out is missing (no pixels, 0 alpha) from the sprite, and everything else is solid white.*/
+
 	if(istype(main) && istype(mask))
-		mask.Blend(rgb(255,255,255), ICON_SUBTRACT) //Make all pixels on the mask as black as possible.
-		mask.Opaque(rgb(255,255,255)) //Make the transparent pixels (background) white.
-		mask.BecomeAlphaMask() //Make all the black pixels vanish (fully transparent), leaving only the white pixels.
+		if(!mask_ready) //Prep the mask if we're using a regular old sprite and not a special-made mask.
+			mask.Blend(rgb(255,255,255), ICON_SUBTRACT) //Make all pixels on the mask as black as possible.
+			mask.Opaque(rgb(255,255,255)) //Make the transparent pixels (background) white.
+			mask.BecomeAlphaMask() //Make all the black pixels vanish (fully transparent), leaving only the white background pixels.
+
 		main.AddAlphaMask(mask) //Make the pixels in the main icon that are in the transparent zone of the mask icon also vanish (fully transparent).
-		return main
+		return main
\ No newline at end of file
diff --git a/code/modules/mob/living/carbon/human/human.dm b/code/modules/mob/living/carbon/human/human.dm
index 0cd4b176e0b..78b51cd2556 100644
--- a/code/modules/mob/living/carbon/human/human.dm
+++ b/code/modules/mob/living/carbon/human/human.dm
@@ -849,7 +849,7 @@
 				return
 			var/read = 0
 			var/perpname = get_visible_name(TRUE)
-			
+
 			for(var/datum/data/record/E in data_core.general)
 				if(E.fields["name"] == perpname)
 					for(var/datum/data/record/R in data_core.medical)
@@ -1470,12 +1470,12 @@
 	var/obj/item/organ/internal/eyes/eyes = get_int_organ(/obj/item/organ/internal/eyes)
 	var/obj/item/organ/internal/cyberimp/eyes/eye_implant = get_int_organ(/obj/item/organ/internal/cyberimp/eyes)
 	if(istype(dna.species) && dna.species.eyes)
-		var/icon/eyes_icon = new/icon('icons/mob/human_face.dmi', dna.species.eyes)
+		var/icon/eyes_icon = new /icon('icons/mob/human_face.dmi', dna.species.eyes)
 		if(eye_implant) //Eye implants override native DNA eye colo(u)r
 			eyes_icon = eye_implant.generate_icon()
 		else if(eyes)
 			eyes_icon = eyes.generate_icon()
-		else
+		else //Error 404: Eyes not found!
 			eyes_icon.Blend("#800000", ICON_ADD)
 
 		return eyes_icon
@@ -1484,8 +1484,8 @@
 	var/obj/item/organ/external/head/head_organ = get_organ("head")
 	var/datum/sprite_accessory/hair/hair_style = GLOB.hair_styles_full_list[head_organ.h_style]
 	var/icon/hair = new /icon("icon" = hair_style.icon, "icon_state" = "[hair_style.icon_state]_s")
-	var/mutable_appearance/MA = mutable_appearance(get_icon_difference(get_eyecon(), hair), layer = LIGHTING_LAYER + 1)
-	MA.plane = LIGHTING_PLANE
+	var/mutable_appearance/MA = mutable_appearance(get_icon_difference(get_eyecon(), hair), layer = ABOVE_LIGHTING_LAYER)
+	MA.plane = ABOVE_LIGHTING_PLANE
 	return MA //Cut the hair's pixels from the eyes icon so eyes covered by bangs stay hidden even while on a higher layer.
 
 /*Used to check if eyes should shine in the dark. Returns the image of the eyes on the layer where they will appear to shine.
diff --git a/code/modules/surgery/organs/organ_icon.dm b/code/modules/surgery/organs/organ_icon.dm
index f291f61c96d..5a4a1e483e7 100644
--- a/code/modules/surgery/organs/organ_icon.dm
+++ b/code/modules/surgery/organs/organ_icon.dm
@@ -87,67 +87,67 @@ var/global/list/limb_icon_cache = list()
 			else if(s_col)
 				mob_icon.Blend(s_col, ICON_ADD)
 
+	if(owner) //Maintains overlays on disembodied parts.
+		cut_overlays()
+
 	dir = EAST
 	icon = mob_icon
 
 	return mob_icon
 
 /obj/item/organ/external/head/get_icon()
-
 	..()
-	overlays.Cut()
 	if(!owner)
 		return
 
 	if(dna.species.has_organ["eyes"])
 		var/icon/eyes_icon = owner.get_eyecon()
 		if(eyes_icon)
-			mob_icon.Blend(eyes_icon, ICON_OVERLAY)
-			overlays |= eyes_icon
+			add_overlay(eyes_icon)
 
 	if(owner.lip_style && (LIPS in dna.species.species_traits))
-		var/icon/lip_icon = new/icon('icons/mob/human_face.dmi', "lips_[owner.lip_style]_s")
-		overlays |= lip_icon
-		mob_icon.Blend(lip_icon, ICON_OVERLAY)
+		add_overlay(mutable_appearance('icons/mob/human_face.dmi', "lips_[owner.lip_style]_s")) //Hefty icon not necessary.
 
 	var/head_marking = owner.m_styles["head"]
-	if(head_marking && head_marking != "None")
+	if(head_marking)
 		var/datum/sprite_accessory/head_marking_style = GLOB.marking_styles_list[head_marking]
 		if(head_marking_style && head_marking_style.species_allowed && (dna.species.name in head_marking_style.species_allowed) && head_marking_style.marking_location == "head")
-			var/icon/h_marking_s = new/icon("icon" = head_marking_style.icon, "icon_state" = "[head_marking_style.icon_state]_s")
+			var/icon/h_marking_s = new /icon("icon" = head_marking_style.icon, "icon_state" = "[head_marking_style.icon_state]_s")
 			if(head_marking_style.do_colouration)
 				h_marking_s.Blend(owner.m_colours["head"], ICON_ADD)
-			overlays |= h_marking_s
+			add_overlay(h_marking_s)
 
-	if(ha_style)
-		var/datum/sprite_accessory/head_accessory_style = GLOB.head_accessory_styles_list[ha_style]
-		if(head_accessory_style && head_accessory_style.species_allowed && (dna.species.name in head_accessory_style.species_allowed))
-			var/icon/head_accessory_s = new/icon("icon" = head_accessory_style.icon, "icon_state" = "[head_accessory_style.icon_state]_s")
-			if(head_accessory_style.do_colouration)
-				head_accessory_s.Blend(headacc_colour, ICON_ADD)
-			overlays |= head_accessory_s
+	if(!((owner.head && (owner.head.flags & BLOCKHAIR)) || (owner.wear_mask && (owner.wear_mask.flags & BLOCKHAIR)))) //Common restriction for all the below features.
+		if(ha_style)
+			var/datum/sprite_accessory/head_accessory_style = GLOB.head_accessory_styles_list[ha_style]
+			if(head_accessory_style && head_accessory_style.species_allowed && (dna.species.name in head_accessory_style.species_allowed))
+				var/icon/head_accessory_s = new /icon("icon" = head_accessory_style.icon, "icon_state" = "[head_accessory_style.icon_state]_s")
+				if(head_accessory_style.do_colouration)
+					head_accessory_s.Blend(headacc_colour, ICON_ADD)
+				add_overlay(head_accessory_s)
 
-	if(f_style)
-		var/datum/sprite_accessory/facial_hair_style = GLOB.facial_hair_styles_list[f_style]
-		if(facial_hair_style && ((facial_hair_style.species_allowed && (dna.species.name in facial_hair_style.species_allowed)) || (dna.species.bodyflags & ALL_RPARTS)))
-			var/icon/facial_s = new/icon("icon" = facial_hair_style.icon, "icon_state" = "[facial_hair_style.icon_state]_s")
-			if(istype(dna.species, /datum/species/slime)) // I am el worstos
-				facial_s.Blend("[owner.skin_colour]A0", ICON_AND) //A0 = 160 alpha.
-			else if(facial_hair_style.do_colouration)
-				facial_s.Blend(facial_colour, ICON_ADD)
-			overlays |= facial_s
+		if(f_style)
+			var/datum/sprite_accessory/facial_hair_style = GLOB.facial_hair_styles_list[f_style]
+			if(facial_hair_style && ((facial_hair_style.species_allowed && (dna.species.name in facial_hair_style.species_allowed)) || (dna.species.bodyflags & ALL_RPARTS)))
+				var/icon/facial_s = new /icon("icon" = facial_hair_style.icon, "icon_state" = "[facial_hair_style.icon_state]_s")
+				if(istype(dna.species, /datum/species/slime)) // I am el worstos
+					facial_s.Blend("[owner.skin_colour]A0", ICON_AND) //A0 = 160 alpha.
+				else if(facial_hair_style.do_colouration)
+					facial_s.Blend(facial_colour, ICON_ADD)
+				add_overlay(facial_s)
 
-	if(h_style && !(owner.head && (owner.head.flags & BLOCKHEADHAIR)))
-		var/datum/sprite_accessory/hair_style = GLOB.hair_styles_full_list[h_style]
-		if(hair_style && ((dna.species.name in hair_style.species_allowed) || (dna.species.bodyflags & ALL_RPARTS)))
-			var/icon/hair_s = new/icon("icon" = hair_style.icon, "icon_state" = "[hair_style.icon_state]_s")
-			if(istype(dna.species, /datum/species/slime)) // I am el worstos
-				hair_s.Blend("[owner.skin_colour]A0", ICON_AND) //A0 = 160 alpha.
-			else if(hair_style.do_colouration)
-				hair_s.Blend(hair_colour, ICON_ADD)
-			overlays |= hair_s
+		if(h_style)
+			if(!owner.isSynthetic() || (owner.isSynthetic() && ((owner.head && (owner.head.flags & BLOCKHEADHAIR)) || (owner.wear_mask && (owner.wear_mask.flags & BLOCKHEADHAIR)))))
+				var/datum/sprite_accessory/hair_style = GLOB.hair_styles_full_list[h_style]
+				if(hair_style && ((dna.species.name in hair_style.species_allowed) || (dna.species.bodyflags & ALL_RPARTS)))
+					var/icon/hair_s = new /icon("icon" = hair_style.icon, "icon_state" = "[hair_style.icon_state]_s")
+					if(istype(dna.species, /datum/species/slime)) // I am el worstos
+						hair_s.Blend("[owner.skin_colour]A0", ICON_AND) //A0 = 160 alpha.
+					else if(hair_style.do_colouration)
+						hair_s.Blend(hair_colour, ICON_ADD)
+					add_overlay(hair_s)
 
-	return mob_icon
+	return mob_icon //Don't need to blend the above into this as it's handled in human/update_icons(). The overlays are for rendering stuff on disembodied heads.
 
 /obj/item/organ/external/proc/get_icon_state(skeletal)
 	var/gender