A Landolt C chart is an eye chart used by eye care professionals and others to measure visual acuity. It contains rows of the letter "C" in various kinds of rotation. The user is asked to state where the limbs of the C are pointing "up, down, left or right" in order to measure the acuity for distant vision. This Landolt CO2 chart tries to illustrate the real condition of CO2 emission in our real life by imitating a Landolt C chart. That is, we cannot distinguish CO2 symbols when we see more and more CO2. Why? Because we are nearsighted.
Assistant Professor of Department of Visual Communication Design, China University of Technology, Taiwan