The ornamental design for an eyemask, as shown and described.
FIG. 1 is a front perspective view of an eye mask, 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 top elevational view thereof;
FIG. 7 is a bottom elevational view thereof;
FIG. 8 is another front perspective view thereof, shown being worn by a user; and,
FIG. 9 is a rear perspective view thereof.
The broken line outline of the partial human figure in FIG. 8 assist in illustrating how the eye mask may appear when in a position of use, but forms no part of the claimed design.