The ornamental design for a lens for a light emitting diode lamp, as shown and described.
FIG. 1 is a front view of a lens for a light emitting diode lamp showing my new design, the rear view, right side view and left side view being identical;
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a sectional view along the center line of the front view; and,
FIG. 5 is a sectional view showing the article in use in a lamp.
The broken lines shown in the drawings are included to illustrate environmental structures only and form no part of the claimed design. The wavy broken lines shown in the drawings indicate the bounds of the claimed design and form no part thereof.