The ornamental design for a float for eyeglasses, as shown and described.
FIG. 1 is a perspective view of a float for eyeglasses showing my new design, the broken line illustration of eyeglasses is for illustrative purposes only and forms no part of the claimed design;
FIG. 2 is a front elevational view thereof, the rear view being a mirror image thereof;
FIG. 3 is an end elevational view thereof, the opposite end view being a mirror image thereof;