To the Editor: I wish to add a few remarks to the interesting discussion between Ami Klin, Ph.D., et al. (1, 2) and Chantal Kemner, Ph.D., and Herman van Engeland, Ph.D., M.D. (3), focusing on the levels of difficulty that social visual fixation poses to persons with autism. Considering a scale from 1 to 10, I will arbitrarily assign level 8 to the paradigm of Dr. Klin et al., the observation of filmed social scenes. Proportionally, an individual could experience level 9 while being engaged in a real, familiar social situation and level 10 in an unfamiliar one. As for the experiment of van der Geest et al. (4), level 3 could be attributed to looking at drawings in which human figures are not so rich in emotional and expressive data (p. 72 of their article).