diff --git a/include/monst.h b/include/monst.h
index d04300171..ecb1391aa 100644
--- a/include/monst.h
+++ b/include/monst.h
@@ -248,6 +248,8 @@ struct monst {
 #define engulfing_u(mon) (u.uswallow && (u.ustuck == (mon)))
 #define helpless(mon) ((mon)->msleeping || !(mon)->mcanmove)
 
+#define mon_perma_blind(mon) (!mon->mcansee && !mon->mblinded)
+
 #define mon_offmap(mon) (((mon)->mstate & (MON_DETACH|MON_MIGRATING|MON_LIMBO|MON_OFFMAP)) != 0)
 
 /* Get the maximum difficulty monsters that can currently be generated,
diff --git a/src/mondata.c b/src/mondata.c
index 282da195a..d66b54cca 100644
--- a/src/mondata.c
+++ b/src/mondata.c
@@ -226,6 +226,10 @@ can_blnd(
     if (!haseyes(mdef->data))
         return FALSE;
 
+    /* if monster has been permanently blinded, the deed is already done */
+    if (!is_you && mon_perma_blind(mdef))
+        return FALSE;
+
     /* /corvus oculum corvi non eruit/
        a saying expressed in Latin rather than a zoological observation:
        "a crow will not pluck out the eye of another crow"
diff --git a/src/potion.c b/src/potion.c
index a4701b1bf..40df5d931 100644
--- a/src/potion.c
+++ b/src/potion.c
@@ -1786,7 +1786,7 @@ potionhit(struct monst *mon, struct obj *obj, int how)
             mon_adjust_speed(mon, 1, obj);
             break;
         case POT_BLINDNESS:
-            if (haseyes(mon->data)) {
+            if (haseyes(mon->data) && !mon_perma_blind(mon)) {
                 int btmp = 64 + rn2(32)
                             + rn2(32) * !resist(mon, POTION_CLASS, 0, NOTELL);