I have been playing with cover ideas for Intense Seeing. Here is my latest effort.
The eye is re-drawn from an Isaac Newton book on Optics (Optice, sive, De reflexionibus, refractionibus, inflexionibus et coloribus lucis : libri tres. - Londini: Impensis S. Smith & B. Walford, 1706. - getr. Zählung : 15 Falttafeln). Which is available on the Max-Planck Institute for the History of Science.
I broke the lines down into dithered points - so that from a distance it looks like a line and close up its a set of grey dosts.