What is the main function of the Na+/K+/ATPase pump in the lens?

The primary role of the Na+/K+/ATPase pump in the lens is to maintain the ionic balance and osmotic environment essential for lens transparency and proper refractive function. This pump actively transports sodium ions (Na+) out of the lens fibers while simultaneously bringing potassium ions (K+) into the lens.

By moving Na+ out of the lens cells, the pump helps prevent excessive intracellular sodium accumulation, which is critical for maintaining the low sodium concentrations required for proper lens metabolism and hydration. This movement of Na+ is balanced by the influx of K+, which is vital for maintaining the electrical gradient across the cell membrane, influencing cell volume and stability.

The activity of the Na+/K+/ATPase pump ensures the lens fibers remain appropriately hydrated, preventing opacities that could lead to cataract formation. This precise regulation of ion transport is crucial, as the lens must remain clear to allow the efficient passage of light. Thus, the correct answer reflects the essential role of the Na+/K+/ATPase pump in maintaining lens health and functionality.