What is the term for corrective lenses that combine three colors?

The correct term for corrective lenses that combine three colors is "apochromatic lenses." Apochromatic lenses are designed to reduce chromatic aberration, allowing for more accurate color correction across the visible spectrum. Unlike typical lenses, which may correct for one or two wavelengths, apochromatic lenses bring three wavelengths of light into focus at the same point, resulting in enhanced sharpness and color fidelity.

This specific design is critical in applications where precise color representation is essential, such as in high-quality cameras, microscopes, and optical instruments. The use of specialized glass and advanced optical designs help achieve this enhanced performance, making apochromatic lenses preferable in situations where color accuracy is paramount.

Other terms listed pertain to different concepts in optics. Monochromatic lenses refer to those that work with a single color of light, while chromatic lenses aren't a standard classification in optics, and duochromatic lenses would only account for two colors, therefore not fulfilling the requirement of combining three colors.