Answer:
it looks good to me, punctuation looks good
The Answer is: It is their only way out.
"Yes," replied the Professor, looking at me calmly from under his spectacles, "it is the only chance which remains to us of ever escaping from the interior of the earth to the light of day."
Possibly it depends on how good their eye sight is in the one eye i mean if a cyclops can do it then he should be able to