Mobilized by electricity

SCIENCE sciencemag.org C R E D IT : J . O . M Ú N E R A E T A L . C E L L S T E M C E L L 2 1 , 5 1 (2 0 17 ) © C E L L P R E S S refractive index of the lens is varied according to the curvature. Cai et al. show that the lenses of squid eyes have an internal structure containing a set of globular proteins that form a gradient of colloidal particles to counter spherical aberration (see the Perspective by Madl). Thus, the evolutionary process has used the principles of patchy colloid theory to construct a self-assembling, complex optical device. —MSL Science, this issue p. 564; see also p. 546