Comparative study of rhodamine-nanoparticle composite lenses for color blindness correction: TiO₂ versus ZnO performance in selective green wavelength filtering

We present a comparative study of rhodamine-based nanocomposite lenses for red-green color blindness correction. Three systems were examined: rhodamine alone, rhodamine–TiO₂, and rhodamine–ZnO. The goal was selective absorption in the 520–560 nm range, critical for deuteranopia and protanopia. UV–Vis analysis showed rhodamine–TiO₂ achieved superior filtering (99.72% at 550 nm) compared to rhodamine–ZnO (95.85%) and rhodamine alone (98.39%). Optimal filtering was achieved when lenses were dip-coated using 60 mL of rhodamine solution. Rhodamine–TiO₂ also produced the desired W-shaped transmission curve, blocking green wavelengths while preserving blue and red. These results identify rhodamine–TiO₂ composites as the most effective system for color blindness correction.