var eye2;

​

function setup() {

  createCanvas(400, 400);

  eye1 = {

    x: width / 2 - 24,

    y: height / 2,

    rad: 32

  };

  eye2 = {

    x: width / 2 + 24,

    y: height / 2,

    rad: 32

  }

}

​

function draw() {

  background(220);

​

  var ang = atan2(mouseY - eye1.y, mouseX - eye1.x);

  var rad = dist(eye1.x, eye1.y, mouseX, mouseY) / eye1.rad;

  fill(255);

  ellipse(eye1.x, eye1.y, eye1.rad);

  fill(0);

  ellipse(eye1.x + rad * cos(ang), eye1.y + rad * sin(ang), eye1.rad / 4);

  ang = atan2(mouseY - eye2.y, mouseX - eye2.x);  

  rad = dist(eye2.x, eye2.y, mouseX, mouseY) / eye2.rad;

  fill(255);

  ellipse(eye2.x, eye2.y, eye2.rad);

  fill(0);

  ellipse(eye2.x + rad * cos(ang), eye2.y + rad * sin(ang), eye2.rad / 4);

}