Is the eye kept open for Mohs Surgery on lower eyelid?

Typically most surgeons will place a drop of Tetracaine in the affected/planned procedure eye prior to beginning surgery.  This is a topical anesthetic that will completely numb the eye.  Then a small delicate shield can be placed comfortably in the eye so that you can effectively ignore the actual technical aspect of the procedure.  If they provide you a small dose of Valium this will also relax you during the procedure and make the process very reasonable. 
 

The eyelids are a very common location to develop skin cancer, and a common area to perform Mohs surgery. Because the Mohs technique removes skin cancer while sparing healthy tissue, the surgery is ideal for tumors that occur in cosmetic and functionally important areas such as the eyelid, ear, nose and lips. It is understandable to be nervous about a surgery in such a sensitive area. A number of techniques can be used to protect the eye when performing surgery in this location. Often, a temporary eye shield can be used to cover the eye, almost like a contact lens during the surgery. This helps prevent any damage to eye from the sharp instruments used during the surgery. The eye shields are typically opaque, so you can't see through them.

Mohs Surgery is commonly performed on the eyelid.  If you are anxious let the surgeon know and ask for some medicine such as Ativan or Valium which can take the edge off for you.  Sometimes an eyeshield is placed to cover and protect the eye when a tumor is very close to the eye.  The great advantage of Mohs Surgery is the high cure rate and tissue sparing nature of the procedure.