The focal distance of a point on the parabola $y^2=8x$ is 10. Its coordinates are 

Let $\left(x_1, y_1\right)$ be a point on parabola. Focal distance $=10\Rightarrow x_1+a=10\Rightarrow x_1+2=10\Rightarrow x_1=8$

$\left(8, y_1\right)$ is a point on $y^2=8x$$\Rightarrow y_1^2=8\left(8\right)\Rightarrow y_1=\pm 8.$    

     $\therefore$ The point is $\left(8, \pm 8\right)$.