Eikonal 2.0: General Solutions for Modified Eikonal Equations

We find implicit general solutions for modified eikonal equations $u_a{u}_a=F(u_t)$, where lower indices at dependent variables designate derivatives, $a=1,2,\mathrm{.}\mathrm{.},n$, and summation is implied over the repeated indices. We will consider the general solutions and symmetries of these equations.