Diagnostic set used by The Corneal Laser Centre, 1997.
© Science Museum / Science & Society Picture Library
Featured is the ChromaGen haploscopic contact lens system for improving defective colour vision. Contained within the set is a booklet by D A Harris 'ChromaGen Clinical Procedures'. Most colour blindnes is inherited, and affects more men than women. The condition is also known as Daltonism, after the chemist John Dalton (1766-1844), who suffered from it, and usually involves confusion between red, green and yellow.