touch reflex is quicker then sight reflex, touch reflex is linked directly to the hind brain thus there is no cognitive thought involved in the reaction.

sight reflex travels through the higher level cognitive brain, there is a direct link to the hind brain (specifically the amygdala), this creates the initial startle/flinch response, but it then consults the memory and other higher order sytems to evaluate the stimulus. there is a lot of information provided by sight and the cognitive part of the brain has to sort out the appropriate match and response.

touch stimulus on the other hand does not contain that much information , there is really only hot, cold. pressure, and impact. the reaction is wired ( and can be learned hence chi sao) to the specific stimulus. you touch something hot and you quickly remove your hand with out thought, you feel pressure and you automatically either resist it or move with it depending on your wiring.

through balance into the equation and you have the simple , primarily unconscious and natural touch reflex based control.

but as mentioned this is OT

Sorry just to drag this even further...

Talking on the use of sight to trigger the startle reflex empowered through the sympathetic nervous system (fight or flight) you can use the peripheral vision to engage the parasympathetic nervous (rest and recuperation) and expand your perception so that it bypasses the 'startle response'. It requires a very big shift in our consciousness to move away from thinking in a 'bit to bit' disjointed fashion and develop our ability to think fluidly without being fixated and drawn to shiny objects which bring a fluid state of thinking to a complete standstill.

I've only had a quick look but I found this link:

http://www.practicaleq.com/peripheral.html

Learning to see 'panoramically' in combat greatly reduces the tunnel vision associated with adrenaline dumps by keeping us focused on the complete picture rather than having a attention drawn to specifics where we can be caught out.