<div class="fof">
  <canvas></canvas>
</div>
body {
  background: #000;
  overflow: hidden;
}

.fof {
  margin: 10px 0;
}

.fof canvas,
.fof img {
  position: relative;
	width: 100%;
	height: 100%;
	margin-bottom: 20px;
	z-index: 1;
	
	background: #000;
}
// The 404 page from my site http://hakim.se/404
(function(){
  
  var DISPLAY_WIDTH = window.innerWidth,
    DISPLAY_HEIGHT = window.innerHeight,
		DISPLAY_DURATION = 10;
	
	var	mouse = { x: 0, y: 0 },
		container,
		canvas,
		context,
		startTime,
		eyes;
	
	function initialize() {
		container = document.querySelector( '.fof' );
		canvas = document.querySelector( '.fof>canvas' );
		
		if( canvas ) {
			canvas.width = DISPLAY_WIDTH;
			canvas.height = DISPLAY_HEIGHT;
			
			context = canvas.getContext( '2d' );
			
			window.addEventListener( 'mousemove', function( event ) {
				mouse.x = event.clientX;
				mouse.y = event.clientY;
			}, false );
			
			eyes = [
				new Eye( canvas,   0.19, 0.80,   0.88,    0.31 ), 
				new Eye( canvas,   0.10, 0.54,   0.84,    0.32 ), 
				new Eye( canvas,   0.81, 0.13,   0.63,    0.33 ), 
				new Eye( canvas,   0.89, 0.19,   0.58,    0.34 ), 
				new Eye( canvas,   0.40, 0.08,   0.97,    0.35 ), 
				new Eye( canvas,   0.64, 0.74,   0.57,    0.36 ), 
				new Eye( canvas,   0.41, 0.89,   0.56,    0.37 ), 
				new Eye( canvas,   0.92, 0.89,   0.75,    0.38 ), 
				new Eye( canvas,   0.27, 0.20,   0.87,    0.39 ), 
				new Eye( canvas,   0.17, 0.46,   0.68,    0.41 ), 
				new Eye( canvas,   0.71, 0.29,   0.93,    0.42 ), 
				new Eye( canvas,   0.84, 0.46,   0.54,    0.43 ), 
				new Eye( canvas,   0.93, 0.35,   0.63,    0.44 ), 
				new Eye( canvas,   0.77, 0.82,   0.85,    0.45 ), 
				new Eye( canvas,   0.36, 0.74,   0.90,    0.46 ), 
				new Eye( canvas,   0.13, 0.24,   0.85,    0.47 ), 
				new Eye( canvas,   0.58, 0.20,   0.77,    0.48 ), 
				new Eye( canvas,   0.55, 0.84,   0.87,    0.50 ), 
        
        new Eye( canvas,   0.50, 0.50,   5.00,    0.10 ),
			];
			
			startTime = Date.now();
			
			animate();
		}
	}
	
	function animate() {
		// The number of seconds that have passed since initialization
		var seconds = ( Date.now() - startTime ) / 1000;
		
		// Out with the old ...
		context.clearRect( 0, 0, DISPLAY_WIDTH, DISPLAY_HEIGHT );
		
		// ... in with the new
		for( var i = 0, len = eyes.length; i < len; i++ ) {
			var eye = eyes[i];
			
			if( seconds > eye.activationTime * DISPLAY_DURATION ) {
				eye.activate();
			};
			
			eye.update( mouse );
		}
		
		requestAnimFrame( animate );
	}
	
  setTimeout( initialize, 1 );
  
})();


function Eye( canvas, x, y, scale, time ) {
	this.canvas = canvas;
	this.context = this.canvas.getContext( '2d' )
	
	// The time at which this eye will come alive
	this.activationTime = time;
	
	// The speed at which the iris follows the mouse
	this.irisSpeed = 0.01 + ( Math.random() * 0.2 ) / scale;
	
	// The speed at which the eye opens and closes
	this.blinkSpeed = 0.2 + ( Math.random() * 0.2 );
	this.blinkInterval = 5000 + 5000 * ( Math.random() );
	
	// Timestamp of the last blink
	this.blinkTime = Date.now();
	
	this.scale = scale;
	this.size = 70 * scale;
	
	this.x = x * canvas.width; 
	this.y = y * canvas.height + ( this.size * 0.15 );
	
	this.iris = {
		x: this.x,
		y: this.y - ( this.size * 0.1 ),
		size: this.size * 0.2
	};
	
	this.pupil = {
		width: 2 * scale,
		height: this.iris.size * 0.75
	};
	
	this.exposure = {
		top: 0.1 + ( Math.random() * 0.3 ),
		bottom: 0.5 + ( Math.random() * 0.3 ),
		current: 0,
		target: 1
	};
	
	// Affects the amount of inner shadow
	this.tiredness = ( 0.5 - this.exposure.top ) + 0.1;
	
	this.isActive = false;
	
	this.activate = function() {
		this.isActive = true;
	}
	
	this.update = function( mouse ) {
		if( this.isActive === true ) {
			this.render( mouse );
		}
	}
	
	this.render = function( mouse ) {
		var time = Date.now();
		
		if( this.exposure.current < 0.012 ) {
			this.exposure.target = 1;
		}
		else if( time - this.blinkTime > this.blinkInterval ) {
			this.exposure.target = 0;
			this.blinkTime = time;
		}
		
		this.exposure.current += ( this.exposure.target - this.exposure.current ) * this.blinkSpeed;
		
		// Eye left/right
		var el = { x: this.x - ( this.size * 0.8 ), y: this.y - ( this.size * 0.1 ) };
		var er = { x: this.x + ( this.size * 0.8 ), y: this.y - ( this.size * 0.1 ) };
		
		// Eye top/bottom
		var et = { x: this.x, y: this.y - ( this.size * ( 0.5 + ( this.exposure.top * this.exposure.current ) ) ) };
		var eb = { x: this.x, y: this.y - ( this.size * ( 0.5 - ( this.exposure.bottom * this.exposure.current ) ) ) };
		
		// Eye inner shadow top
		var eit = { x: this.x, y: this.y - ( this.size * ( 0.5 + ( ( 0.5 - this.tiredness ) * this.exposure.current ) ) ) };
		
		// Eye iris
		var ei = { x: this.x, y: this.y - ( this.iris.size ) };
		
		// Offset the iris depending on mouse position
		var eio = { 
			x: ( mouse.x - ei.x ) / ( window.innerWidth - ei.x ), 
			y: ( mouse.y ) / ( window.innerHeight )
		};
		
		// Apply the iris offset
		ei.x += eio.x * 16 * Math.max( 1, this.scale * 0.4 );
		ei.y += eio.y * 10 * Math.max( 1, this.scale * 0.4 );
		
		this.iris.x += ( ei.x - this.iris.x ) * this.irisSpeed;
		this.iris.y += ( ei.y - this.iris.y ) * this.irisSpeed;
		
		// Eye fill drawing
		this.context.fillStyle = 'rgba(255,255,255,1.0)';
		this.context.strokeStyle = 'rgba(100,100,100,1.0)';
		this.context.beginPath();
		this.context.lineWidth = 3;
		this.context.lineJoin = 'round';
		this.context.moveTo( el.x, el.y );
		this.context.quadraticCurveTo( et.x, et.y, er.x, er.y );
		this.context.quadraticCurveTo( eb.x, eb.y, el.x, el.y );
		this.context.closePath();
		this.context.stroke();
		this.context.fill();
		
		// Iris
		this.context.save();
		this.context.globalCompositeOperation = 'source-atop';
		this.context.translate(this.iris.x*0.1,0);
		this.context.scale(0.9,1);
		this.context.strokeStyle = 'rgba(0,0,0,0.5)';
		this.context.fillStyle = 'rgba(130,50,90,0.9)';
		this.context.lineWidth = 2;
		this.context.beginPath();
		this.context.arc(this.iris.x, this.iris.y, this.iris.size, 0, Math.PI*2, true);
		this.context.fill();
		this.context.stroke();
		this.context.restore();
		
		// Iris inner
		this.context.save();
		this.context.shadowColor = 'rgba(255,255,255,0.5)';
		this.context.shadowOffsetX = 0;
		this.context.shadowOffsetY = 0;
		this.context.shadowBlur = 2 * this.scale;
		this.context.globalCompositeOperation = 'source-atop';
		this.context.translate(this.iris.x*0.1,0);
		this.context.scale(0.9,1);
		this.context.fillStyle = 'rgba(255,255,255,0.2)';
		this.context.beginPath();
		this.context.arc(this.iris.x, this.iris.y, this.iris.size * 0.7, 0, Math.PI*2, true);
		this.context.fill();
		this.context.restore();
		
		// Pupil
		this.context.save();
		this.context.globalCompositeOperation = 'source-atop';
		this.context.fillStyle = 'rgba(0,0,0,0.9)';
		this.context.beginPath();
		this.context.moveTo( this.iris.x, this.iris.y - ( this.pupil.height * 0.5 ) );
		this.context.quadraticCurveTo( this.iris.x + ( this.pupil.width * 0.5 ), this.iris.y, this.iris.x, this.iris.y + ( this.pupil.height * 0.5 ) );
		this.context.quadraticCurveTo( this.iris.x - ( this.pupil.width * 0.5 ), this.iris.y, this.iris.x, this.iris.y - ( this.pupil.height * 0.5 ) );
		this.context.fill();
		this.context.restore();
		
		this.context.save();
		this.context.shadowColor = 'rgba(0,0,0,0.9)';
		this.context.shadowOffsetX = 0;
		this.context.shadowOffsetY = 0;
		this.context.shadowBlur = 10;
		
		// Eye top inner shadow
		this.context.fillStyle = 'rgba(120,120,120,0.2)';
		this.context.beginPath();
		this.context.moveTo( el.x, el.y );
		this.context.quadraticCurveTo( et.x, et.y, er.x, er.y );
		this.context.quadraticCurveTo( eit.x, eit.y, el.x, el.y );
		this.context.closePath();
		this.context.fill();
		
		this.context.restore();
		
	}
}

// shim with setTimeout fallback from http://paulirish.com/2011/requestanimationframe-for-smart-animating/
window.requestAnimFrame = (function(){
  return  window.requestAnimationFrame       || 
          window.webkitRequestAnimationFrame || 
          window.mozRequestAnimationFrame    || 
          window.oRequestAnimationFrame      || 
          window.msRequestAnimationFrame     || 
          function(/* function */ callback, /* DOMElement */ element){
            window.setTimeout(callback, 1000 / 60);
          };
})();

External CSS

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External JavaScript

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