diff --git a/example01/index.html b/example01/index.html
index c6acee2..a2647e4 100644
--- a/example01/index.html
+++ b/example01/index.html
@@ -5,9 +5,7 @@
 <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">
 
 <script id="shader-fs" type="x-shader/x-fragment">
-  #ifdef GL_ES
-  precision highp float;
-  #endif
+  precision mediump float;
 
   varying vec2 vPosition;
 
diff --git a/example02/index.html b/example02/index.html
index 7741a38..8dc0032 100644
--- a/example02/index.html
+++ b/example02/index.html
@@ -9,9 +9,7 @@
 
 
 <script id="color-shader-fs" type="x-shader/x-fragment">
-  #ifdef GL_ES
-  precision highp float;
-  #endif
+  precision mediump float;
 
   varying vec4 vColor;
 
@@ -40,9 +38,7 @@
 
 
 <script id="mandelbrot-shader-fs" type="x-shader/x-fragment">
-  #ifdef GL_ES
-  precision highp float;
-  #endif
+  precision mediump float;
 
   varying vec2 vPlotPosition;
   varying vec4 vColor;
diff --git a/example03/particles-01-noenable.html b/example03/particles-01-noenable.html
index 2591506..5fc7deb 100644
--- a/example03/particles-01-noenable.html
+++ b/example03/particles-01-noenable.html
@@ -6,9 +6,7 @@
 
 
 <script id="shader-fs" type="x-shader/x-fragment">
-  #ifdef GL_ES
-  precision highp float;
-  #endif
+  precision mediump float;
 
   uniform vec4 uColor;
 
diff --git a/example03/particles-01.html b/example03/particles-01.html
index 77a5a03..c713902 100644
--- a/example03/particles-01.html
+++ b/example03/particles-01.html
@@ -6,9 +6,7 @@
 
 
 <script id="shader-fs" type="x-shader/x-fragment">
-  #ifdef GL_ES
-  precision highp float;
-  #endif
+  precision mediump float;
 
   uniform vec4 uColor;
 
diff --git a/example03/particles-02.html b/example03/particles-02.html
index 27fc225..1d0b7ac 100644
--- a/example03/particles-02.html
+++ b/example03/particles-02.html
@@ -6,9 +6,7 @@
 
 
 <script id="shader-fs" type="x-shader/x-fragment">
-  #ifdef GL_ES
-  precision highp float;
-  #endif
+  precision mediump float;
 
   uniform vec4 uColor;
 
diff --git a/example03/particles-03.html b/example03/particles-03.html
index 942fe3a..c5b07f6 100644
--- a/example03/particles-03.html
+++ b/example03/particles-03.html
@@ -6,9 +6,7 @@
 
 
 <script id="shader-fs" type="x-shader/x-fragment">
-  #ifdef GL_ES
-  precision highp float;
-  #endif
+  precision mediump float;
 
   uniform vec4 uColor;
 
diff --git a/lesson01/index.html b/lesson01/index.html
index 48bf163..36f5560 100644
--- a/lesson01/index.html
+++ b/lesson01/index.html
@@ -7,9 +7,7 @@
 <script type="text/javascript" src="glMatrix-0.9.5.min.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     void main(void) {
         gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);
diff --git a/lesson02/index.html b/lesson02/index.html
index 4ea7749..947d97e 100644
--- a/lesson02/index.html
+++ b/lesson02/index.html
@@ -7,9 +7,7 @@
 <script type="text/javascript" src="glMatrix-0.9.5.min.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec4 vColor;
 
diff --git a/lesson03/index.html b/lesson03/index.html
index dff2d15..ee8dd63 100644
--- a/lesson03/index.html
+++ b/lesson03/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec4 vColor;
 
diff --git a/lesson04/index.html b/lesson04/index.html
index c3abb74..fb59f98 100644
--- a/lesson04/index.html
+++ b/lesson04/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec4 vColor;
 
diff --git a/lesson05/index.html b/lesson05/index.html
index ad472fb..165e1f2 100644
--- a/lesson05/index.html
+++ b/lesson05/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
 
diff --git a/lesson06/index.html b/lesson06/index.html
index 9805336..b6a2b28 100644
--- a/lesson06/index.html
+++ b/lesson06/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
 
diff --git a/lesson07/index.html b/lesson07/index.html
index 36453ff..c842528 100644
--- a/lesson07/index.html
+++ b/lesson07/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
     varying vec3 vLightWeighting;
diff --git a/lesson08/index.html b/lesson08/index.html
index 1519c6c..b78135e 100644
--- a/lesson08/index.html
+++ b/lesson08/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
     varying vec3 vLightWeighting;
diff --git a/lesson09/index.html b/lesson09/index.html
index f18abf3..99f568a 100644
--- a/lesson09/index.html
+++ b/lesson09/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
 
diff --git a/lesson10/index.html b/lesson10/index.html
index bab7749..a189fcc 100644
--- a/lesson10/index.html
+++ b/lesson10/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
 
diff --git a/lesson11/index.html b/lesson11/index.html
index 8a694e6..f3fa74a 100644
--- a/lesson11/index.html
+++ b/lesson11/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
     varying vec3 vLightWeighting;
diff --git a/lesson12/index.html b/lesson12/index.html
index a2ba26b..ff1709b 100644
--- a/lesson12/index.html
+++ b/lesson12/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="shader-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
     varying vec3 vLightWeighting;
diff --git a/lesson13/index.html b/lesson13/index.html
index 7381086..e961261 100644
--- a/lesson13/index.html
+++ b/lesson13/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="per-vertex-lighting-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
     varying vec3 vLightWeighting;
@@ -68,9 +66,7 @@
 
 
 <script id="per-fragment-lighting-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
     varying vec3 vTransformedNormal;
diff --git a/lesson14/index.html b/lesson14/index.html
index d8379c5..0c07947 100644
--- a/lesson14/index.html
+++ b/lesson14/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="per-fragment-lighting-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
     varying vec3 vTransformedNormal;
diff --git a/lesson15/index.html b/lesson15/index.html
index cb60775..d53d0b4 100644
--- a/lesson15/index.html
+++ b/lesson15/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="per-fragment-lighting-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
     varying vec3 vTransformedNormal;
diff --git a/lesson16/index.html b/lesson16/index.html
index 4a4f196..558a20e 100644
--- a/lesson16/index.html
+++ b/lesson16/index.html
@@ -8,9 +8,7 @@
 <script type="text/javascript" src="webgl-utils.js"></script>
 
 <script id="per-fragment-lighting-fs" type="x-shader/x-fragment">
-    #ifdef GL_ES
-    precision highp float;
-    #endif
+    precision mediump float;
 
     varying vec2 vTextureCoord;
     varying vec3 vTransformedNormal;
@@ -816,7 +814,7 @@
     Moon texture courtesy of <a href="http://maps.jpl.nasa.gov/">the Jet Propulsion Laboratory</a>.
     <br/>
     <br/>
-    
+
     <a href="http://learningwebgl.com/blog/?p=1786">&lt;&lt; Back to Lesson 16</a><br />
 </body>