The ornamental design for a light-reducing filter for night vision device, as shown and described.
FIG. 1 is a front perspective view of a light-reducing filter for night vision device showing our new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right side elevational view thereof, the left side elevational view being a mirror image thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof; and,
FIG. 7 is a front perspective view thereof, attached to a night vision device, the broken lines shown are included for the purpose of illustrating environmental subject matter only and form no part of the claimed design.