As you begin to travel at higher and higher velocities, strange things begin to occur. You start to see more and more of what is behind you crowd in tighter and tighter with what's in front of you. Also, things which are behind you begin to take on a reddish hue due to the Doppler effect while things in front of you take on a blueish hue due to the same effect.

Also, if you were traveling at 25c (one quarter the speed of light), anything in your path (that is not moving in the same direction as you at close to your same velocity) which collides with you, no matter how small and low in mass, for example a leaf falling from a tree, will hit you with enough force to blow a hole cleanly through your body. Every little piece of particulate matter becomes a lethal bullet threatening to pierce the hull of your ship.

This is why the amorphous buffer field is so vital to survival in space. It is made up of trillions of microscopic simple swarm-intelligence robots that can absorb or deflect any impacting material like a bullet being fired into a swimming pool. Almost all of the energy of the impact is converted into a big splash or wave which is barely even felt within the ship. When the object is absorbed, the extra mass is either utilized to make repairs, or is can be converted into fuel. If not converted to fuel then simply ejected in the opposite direction the vessel is traveling to gain a very slight increase in velocity to further economize the fuel (although the gain is negligible, keep in mind that millions of micrometeorites are impacting your ship each day, so the cumulative effect is quite worthwhile).