Code as Material
Ben Fry and Casey Reas

let eyes = [];

function setup() {
  createCanvas(windowWidth, windowHeight);
  noStroke();
  let divs = 7;
  let diameter = windowWidth / divs;
  let ydivs = ceil(windowHeight / diameter);
  let numeyes = (divs * ydivs);
  print(numeyes);
  let x = -diameter * floor(divs / 2);
  let y = 0;
  if (ydivs % 2 == 0) {
    y = -diameter * floor(ydivs / 2) + diameter / 2;
  } else {
    y = -diameter * floor(ydivs / 2);
  }
  let xcount = 0;
  let ycount = 0;
  for (let i = 0; i < numeyes; i++) {
    eyes.push(new Eye(x, y, diameter * 0.9));
    x += diameter;
    xcount++;
    if (xcount == divs) {
      xcount = 0;
      x = -diameter * floor(divs / 2);
      y += diameter;
    }
  }
}

function draw() {
  updateEyes();
}

function updateEyes() {
  background(102);
  translate(width / 2, height / 2);
  for (let i = 0; i < eyes.length; i++) {
    eyes[i].update();
    eyes[i].display();
  }
}

class Eye {
  constructor(tx, ty, ts) {
    this.x = tx;
    this.y = ty;
    this.size = ts;
    this.radius = ts / 4.0;
    this.currentRadius = 0.0;
  }

  update() {
    this.angle = atan2(mouseY - height / 2 - this.y, mouseX - width / 2 - this.x);
    if (mouseIsPressed) {
      this.currentRadius += (this.radius - this.currentRadius) * 0.1;
    } else {
      this.currentRadius += (-this.currentRadius) * 0.1;
    }
  }

  display() {
    push();
    translate(this.x, this.y);
    fill(255);
    ellipse(0, 0, this.size, this.size);
    rotate(this.angle);
    fill(153, 204, 0);
    ellipse(this.currentRadius, 0, this.size / 2, this.size / 2);
    pop();
  }
}