--- ray/src/rt/dielectric.c	1991/11/12 17:09:55	2.1
+++ ray/src/rt/dielectric.c	1992/11/19 20:30:02	2.3
@@ -53,7 +53,6 @@ m_dielectric(m, r)	/* color a ray which hit something 
 OBJREC  *m;
 register RAY  *r;
 {
-	double  sqrt(), pow();
 	double  cos1, cos2, nratio;
 	COLOR  mcolor;
 	double  mabsorp;
@@ -129,7 +128,7 @@ register RAY  *r;
 			if (m->otype != MAT_DIELECTRIC
 					|| r->rod > 0.0
 					|| r->crtype & SHADOW
-					|| directinvis
+					|| !directvis
 					|| m->oargs.farg[4] == 0.0
 					|| !disperse(m, r, p.rdir, trans))
 #endif
@@ -168,7 +167,6 @@ RAY  *r;
 FVECT  vt;
 double  tr;
 {
-	double  sqrt();
 	RAY  sray, *entray;
 	FVECT  v1, v2, n1, n2;
 	FVECT  dv, v2Xdv;