1.   Areas that control sleep are near areas that control body movements, which explains why eyelids grow heavy with drowsiness and why dreams are full of fictive movements.

2.   Eyelids grow heavy.

3.   My eyelids grow heavier.

4.   There was a fire in the large hearth of this stone kitchen that had once been a stable, and our eyelids grew heavy with the warmth and fatigue.