  The eigenvalue spectrum $\rho(\lambda)$ of the Dirac operator is numerically
calculated in lattice QCD with 2+1 flavors of dynamical domain-wall fermions.
In the high-energy regime, the discretization effects become significant. We
subtract them at the leading order and then take the continuum limit with
lattice data at three lattice spacings. Lattice results for the exponent
$\partial\ln\rho/\partial\ln\lambda$ are matched to continuum perturbation
theory, which is known up to $O(\alpha_s^4)$, to extract the strong coupling
constant $\alpha_s$.
