Abstract
The visibility graph $V(P)$ of a set of points $P$ in the plane is the graph with vertex set $P$ where two vertices $u$ and $v$ are adjacent if and only if there is no point from $P$ on the segment connecting $u$ with $v$. We study the chromatic number of $V(P)$ and show superpolynomial lower bound on the chromatic number in terms of clique number.