This patch fixes cleric lightning not causing blindness
(All other lightning spells cause blindness)

I hope this fix helps. Let me know what you think!
Chris Becker (topher@csh.rit.edu)

More bug fixes and patches can be found at 
http://www.csh.rit.edu/~topher/nethack

diff -aur ..\original\nethack-3.4.3\src\mcastu.c nethack-3.4.3\src\mcastu.c
--- ..\original\nethack-3.4.3\src\mcastu.c	Sun Dec 07 16:39:14 2003
+++ nethack-3.4.3\src\mcastu.c	Fri Jan 02 20:51:00 2004
@@ -515,6 +515,14 @@
 
 	pline("A bolt of lightning strikes down at you from above!");
 	reflects = ureflects("It bounces off your %s%s.", "");
+	   
+	/* copied from zap.c
+	 * Chris Becker (topher@csh.rit.edu)
+	 */
+    You("are blinded by the flash!");
+    make_blinded((long)rnd(100),FALSE);
+    if (!Blind) Your(vision_clears);
+
 	if (reflects || Shock_resistance) {
 	    shieldeff(u.ux, u.uy);
 	    dmg = 0;