The ornamental design for an eyeglassholder, as shown and described.
FIG. 1 is a perspective view of an eyeglass holder showing our new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The portions shown in broken lines in the drawings depict unclaimed subject matter only and form no part of the claimed design. The dot-dash lines represent bounds of associated portions of the eyeglass holder and form no part of the claimed design.