diff --git a/doc/fixes34.4 b/doc/fixes34.4
index 00a14057f..2e45e750e 100644
--- a/doc/fixes34.4
+++ b/doc/fixes34.4
@@ -126,6 +126,7 @@ chatting with quest leader who was brought back from the dead gave warnings
 becoming green slime or mimicking gold violates "never changed form" conduct
 when a monster grew into a higher form which had previously been genocided,
 	the message explaining its fate was only given if it was sensed via ESP
+hero could still see for brief period after being blinded by potion vapors
 
 
 Platform- and/or Interface-Specific Fixes
diff --git a/src/potion.c b/src/potion.c
index f376c1f7a..f36852c75 100644
--- a/src/potion.c
+++ b/src/potion.c
@@ -243,6 +243,13 @@ boolean talk;
 	if (u_could_see ^ can_see_now) {  /* one or the other but not both */
 	    context.botl = 1;
 	    vision_full_recalc = 1;	/* blindness just got toggled */
+	    /* this vision recalculation used to be deferred until
+	       moveloop(), but that made it possible for vision
+	       irregularities to occur (cited case was force bolt
+	       hitting adjacent potion of blindness and then a
+	       secret door; hero was blinded by vapors but then
+	       got the message "a door appears in the wall") */
+	    vision_recalc(0);
 	    if (Blind_telepat || Infravision) see_monsters();
 	}
 }
diff --git a/src/vision.c b/src/vision.c
index 28f63c06f..0bc5fc06f 100644
--- a/src/vision.c
+++ b/src/vision.c
@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)vision.c	3.5	1999/02/18	*/
+/*	SCCS Id: @(#)vision.c	3.5	2005/06/15	*/
 /* Copyright (c) Dean Luick, with acknowledgements to Dave Cohrs, 1990.	*/
 /* NetHack may be freely redistributed.  See license for details.	*/
 
@@ -468,6 +468,8 @@ new_angle(lev, sv, row, col)
  *	+ Right before something is printed. [pline()]
  *	+ Right before we do a vision based operation. [do_clear_area()]
  *	+ screen redraw, so we can renew all positions in sight. [docrt()]
+ *	+ When toggling temporary blindness, in case additional events
+ *	  impacted by vision occur during the same move [make_blinded()]
  *
  * Control flag = 1.  An adjacent vision recalculation.  The hero has moved
  * one square.  Knowing this, it might be possible to optimize the vision