diff --git a/libraries/render-utils/src/DeferredTransform.slh b/libraries/render-utils/src/DeferredTransform.slh
index 59ba0a1b36..6b0e1cd642 100644
--- a/libraries/render-utils/src/DeferredTransform.slh
+++ b/libraries/render-utils/src/DeferredTransform.slh
@@ -122,16 +122,12 @@ float evalZeyeFromZdb(float depth) {
     return frameTransform._depthInfo.x / (depth * frameTransform._depthInfo.y + frameTransform._depthInfo.z);
 }
 
-vec3 evalEyeNormal(vec3 C) {
-    return normalize(cross(dFdx(C), dFdy(C)));
+float evalZdbFromZeye(float Zeye) {
+    return (frameTransform._depthInfo.x - Zeye * frameTransform._depthInfo.z) / (Zeye * frameTransform._depthInfo.y);
 }
 
-vec3 evalEyePositionFromZeye(int side, float Zeye, vec2 texcoord) {
-    // compute the view space position using the depth
-    // basically manually pick the proj matrix components to do the inverse
-    float Xe = (-Zeye * (texcoord.x * 2.0 - 1.0) - Zeye * frameTransform._projection[side][2][0] - frameTransform._projection[side][3][0]) / frameTransform._projection[side][0][0];
-    float Ye = (-Zeye * (texcoord.y * 2.0 - 1.0) - Zeye * frameTransform._projection[side][2][1] - frameTransform._projection[side][3][1]) / frameTransform._projection[side][1][1];
-    return vec3(Xe, Ye, Zeye);
+vec3 evalEyeNormal(vec3 C) {
+    return normalize(cross(dFdx(C), dFdy(C)));
 }
 
 vec3 evalEyePositionFromZdb(int side, float Zdb, vec2 texcoord) {
@@ -142,6 +138,11 @@ vec3 evalEyePositionFromZdb(int side, float Zdb, vec2 texcoord) {
     return eyePos.xyz / eyePos.w;
 }
 
+vec3 evalEyePositionFromZeye(int side, float Zeye, vec2 texcoord) {
+	float Zdb = evalZdbFromZeye(Zeye);
+    return evalEyePositionFromZdb(side, Zdb, texcoord);
+}
+
 ivec2 getPixelPosTexcoordPosAndSide(in vec2 glFragCoord, out ivec2 pixelPos, out vec2 texcoordPos, out ivec4 stereoSide) {
     ivec2 fragPos = ivec2(glFragCoord.xy);