What is it about a professional portrait that grabs you first? If you survey the work of Richard Avedon or other great portrait photographers, much of the spark and life of the images comes from the subject's eyes. Think of the famous close-up portrait of the Afghan girl with sparkling green eyes captured by National Geographic photojournalist Steve McCurry. The eyes lock you in, but it's more than just their vivid color. Much of their depth and shine is due to lighting technique called a catchlight.
A catchlight is any source of natural or artificial light that is purposefully bounced off of the subject's eyes to make them sparkle. The classic positioning of the catchlight sparkle is at 10 o'clock in relation to the iris of the eye. Studio photographers will use an umbrella reflector to aim diffused light into the subject's eyes, but you don't need fancy equipment to achieve the same effect. One photographer recommends using the reflective back of a compact disc to bounce light toward the subject. Another even suggests wearing a white T-shirt to act as a soft reflective surface [source: Rowse].