Fig. 24. A. Ocular myasthenia presenting as unilateral ptosis in an 8-year-old child. B. Levator can be fatigued by sustained upward gaze. C. Increasing ptosis. D. With ptosis accentuated, intravenous edrophonium (Tensilon) relieves fatigued left lid. E. Paradoxically, right lid is paralyzed.