The effects of relativity, such as the relativity of simultaneity, time dilation, and length contraction, are not directly related to the time it takes for light to reach our eyes. These effects are fundamental aspects of space and time as described by the theory of relativity and are considered "real" effects.
In special relativity, the concept of simultaneity is relative and depends on the observer's reference frame. Different observers in relative motion will perceive events to be simultaneous or sequential differently. This effect is not solely due to the time it takes for light to travel but is a consequence of the structure of spacetime.
Time dilation is another effect predicted by relativity. It states that time can pass at different rates for objects moving relative to each other. This effect has been experimentally confirmed and plays a crucial role in various practical applications, such as GPS systems, where the precise timing of signals is essential.
Length contraction, or Lorentz contraction, is the phenomenon where objects in motion appear shorter along the direction of their motion as observed by an outside observer. Again, this effect is a consequence of the geometry of spacetime and is not solely dependent on the time it takes for light to reach our eyes.
It's worth noting that while the transmission of light and the time it takes for light to travel can be influenced by relativity, the effects mentioned above go beyond simple light propagation and are fundamental aspects of the structure of spacetime itself.