I would like to add that not only is the eye most sensitive to green light but that many films have a dip in sensitivity in this region. Even so it is very important not to expose the film to the light until development is at least 50% completed. The self masking of the developed silver is an added safety factor.
The film should be inspected from the base side and not from the emulsion side. This technique takes a bit of experience to do well. The standard time/temperature method is actually more accurate in most circumstances.
A film can also be put in a pre-bath containing certain dyes to decrease the sensitivity of thee film allowing the use of a much brighter light.
This is all correct and I would like to add that before and during the initial development with the panchromatic film covered in total darkness, you let your eyes adjust for about 20 minutes to this very dark green light before inspection.