The ornamental design for eyeglasses for blocking allergens, as shown and described.
FIG. 1 is a perspective view of eyeglasses for blocking allergens;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a first side view thereof;
FIG. 5 is a second side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines shown in the drawings depict parts of the eyeglasses for blocking allergens, are for illustrative purposes only and form no part of the claimed design.