If the vision panel is fire protective glass such as safety wired glass and safety ceramic its size is limited to no more than 100 square inches whether or not sprinklers are present.
Standard vision panel door.
Ada section 404 2 11 requires that at least one of the vision panels in a door and sidelites adjacent to a door be no more than 43 inches 1090 mm above the floor line to provide visibility and safe access for all.
This calculation below is the max height for allowance.
The 2012 ibc model building code contains size limits for vision panels in a 60 or 90 minute door.
To create the maximum vision panel size incompletion the formula is as follows.
With this measurement we subtract the top of the glass to the top of the door.
Vision panels exceeding 100 square inches in 60 and 90 minute doors require fire resistive glazing.