Lindsay nails (half-and-half nails) is an apparent leukonychia of the proximal portion of the nail which is white with distal 20-60% reddish-brown
Philip Gaylord Lindsay (1937 - 2017) was an American physician and psychiatrist. Remembered eponymously for Lindsay nails (1967)
Muehrcke's nails (or Muehrcke lines) are a disorder of the nail bed which can be a reflection of systemic disease. A distinct pattern of paired, white, transverse lines that usually spare the thumbnail and are most commonly in seen in association with hypoalbuminaemia, metabolic stress or chemotherapy.