How come iris can be related to both eyes and plants?

We have learned iris in Lesson 14-1. The prefix for iris, irid(o)- is derived from rainbow (please referred to Lesson 5-3).

However, iris also meaning a plant.

Iris. Source: wikipedia

Iris plant is a monocot with beautiful flowers. The artist Van Gogh drew a famous painting for it. How come tissue in the eye become a plant?

Well, as we mention in this article first, the tissue in our eyes get the name iris because different people has different color of iris. Therefore, the Greek word for rainbow, iridos, is borrowed for describing the tissue in our eyes.

How about the plant iris? Isn't all iris blue?

Actually not. Because that famous painting from Van Gogh, we thought all iris are blue. Actually there are many different shades of colors for iris.

Different colors of iris. Source: wikipedia gallery

Source: Wikipedia Gallery

Source: wiki

Because iris has so many shades of colors, Greek named it iris. That's why the word iris can be used for the tissue in our eyes and also a plant!

Reference.

Wikipedia Iris (anatomy)_Etymology, Iris (plant)