The 4.3 Nordan Tying Forceps Curved are specialized surgical instruments used in ophthalmic surgeries, particularly for tying sutures. The "curved" design provides better access to the surgical site, allowing the surgeon to tie sutures more easily and precisely, especially in areas that are hard to reach. The 4.3 refers to the size of the forceps, indicating a small and delicate instrument suitable for intricate procedures.