A closer look at the iris

IRIS is the name of a beautiful flower, the name of a Greek goddess of the rainbow and also the part of the eye anatomy that gives it its colour, perceptible to the observers. As an ophthalmologist, the iris is the part of the eye that fascinates me the most because of its uniqueness and beauty, and also how strongly yet subtly it controls our vision.

So excited was I about this wonderful piece of eye tissue that several years ago I took myself to a "mini-fellowship" in the United States for a month to learn all about how best to repair it, and in the process co-wrote a textbook chapter on it too.

In the eye, the iris functions like camera shutters, partitioning the eye into front and back, and controlling the amount of light that enters through the pupil, the round aperture in the centre of the iris (which is constricted in light and dilated in the dark) to reach the retina at the back of the eye, where light-induced signals are converted into tiny electrochemical signals that are relayed through our optic nerve to our brain.