Eye diseases were common in ancient times. People often considered blindness as divine punishment (see Exodus 4:11; Deuteronomy 28:28; 2 Kings 6:18; John 9:2–3). The Old Testament prophesies that when the Messiah came he would restore sight to the blind (Matthew 11:4–5; Isaiah 29:18–19; 35:5–6).
Son of David is a title connected to the Messiah and miraculous healings (see Matthew 1:1; 12:23; 15:22; 20:30–31; 2 Samuel 7:12–16).