| abstract |
Photochromatic compositions endowed with light fatigue resistance comprising: (a) at least one photochromatic compound belonging to the group of spiro-indolino-oxazines, spiro-pyrans, or spiro-isoindolino-oxazines; (b) at least one compound belonging to the group of enamines consisting of derivatives of β-ketoesters, or β-ketoamines or 1,3-diketones with primary or secondary aliphatic or aromatic amines. |