“…Many polymer matrices are available for the production of photosensitive materials: various polymethacrylates, polyvinyl acetate (PVA), cellulose acetate (CA), polystyrene (PS), and others [12,16,21]. PMMA is widely used in sensor design and fiber optics technology [22,23]. A PMMA matrix doped with spiropyrans is one of the most prominent photochromic optical sensor materials due to the synergy of the high transparency and thermoplasticity of polar polymers and the pronounced isomerization of the filling photochromic compounds [2,24].…”