TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Copolymer: The copolymer is optionally halogenated alkyl, cycloalkyl, aryl or aralkyl of polystyrene, polyether, polyester, polycarbonate, polycarbamate, polyepoxy, polyurea, polyurethane, polythiourethane, polysiloxane, polyacrylonitrile, polyamide, aliphatic or aromatic polyester, vinylic polymer, cellulose acetate, cellulose triacetate, cellulose acetate-propionate or polyvinylbutryl, copolymers of two or more monomers or mixtures of polymers. SPECIFIC COMPOUNDS - Naphthopyran compound is 3,3-bis(2,4-dimethoxyphenyl)-5-morpholinocarbonyl-3H-naphtho(2,1-b)pyran, 3,3-bis(4-methoxyphenyl)-5-p-tolylcarbamoyl-3H-naphtho-(2,1-b)pyran, 3-(4-dimethylaminophenyl)-3-(4-dimethylaminonapthyl)-5-morpholinocarbonyl-3H-naphtho(2,1-b)pyran, and 3,3-bis(2,4-dimethoxyphenyl)-5-indolinocarbonyl-3H-naphtho(2,1)pyran.    EXAMPLE - (In grams) Catalytic amount of p-toluenesulfonic acid (10 mg) was added to 2-hydroxy-3-indolinocarbonylnaphthalene (0.705) and bis(2,4-dimethyoxyphenyl)-2-propyn-1-ol (0.80) was dissolved in 120 ml of benzene. The resulting mixture was stirred at 60-70 degreesC for 2 hours and washed with water. The organic layer was separated, dried over anhydrous sodium sulfate and the solvent was removed in vacuum. The resultant oil was chromatographed on silica gel, aluminum oxide and crystallized using ether. The yield of 3,3-bis(2,4-methoxyphenyl)-5-indolinocarbonyl-3H-naphtho(2,1-b)pyran powder (A) obtained was (0.3). 10-5 mols of compound A, 0.2 (wt.%) of (2,2'-azobis(2-methylbutyronitrile) was added to tetraethoxylate Bisphenol A dimethylmethacrylate to form a formulation. The formulation was poured into a lens mold of 2 mm thickness and cured by heating at 60 degreesC for 6 hours to form lens sample. The photochromic properties were evaluated in which T0 was 85.6 %, TD15 was 7.0 %, optical induced density was 1.063, time of half darkness which is the kinetics of the return to initial state from equilibrium was 1420 seconds and the maximum absorption in visible spectrum after UV radiation was 514.