True? Body's impulse to breathe is based on CO2?

[oxy60]

Yes, through six layers.
1  Nerve fiber layer
2  Ganglion cell layer
3  Inner plexiform layer
4  Inner nuclear layer
5  Outer plexiform layer
6  Outer nuclear layer

And now I must apologize for being a smart aleck.  I really thought everybody knew this. 

Then my concern is whether we are damaging those other layers. There seems to be no evidence of problems.  A hole or a tear must be repaired or big problems await. It's always a balancing act isn't it?