I was saying the opposite. The claim of time dilation has nothing to do with the visual perception of clocks, which is a common (flawed) example that is used. The visual perception of clocks differing by heading towards or away from a clock is just a phenomenon akin to the Doppler effect.

If you correct for this effect caused by changing distance between the parties, you will still observe a difference in passage of time in the two different inertial frames of reference (each observing the other). In both cases the party taking the measurement will observe that time is passing more slowly in the frame of reference that the measurer sees as moving with respect to the measurer's frame, regardless of whether that motion is toward or away from the measurer.