Polymerizable yellow dyes and their use in ophthalmic lenses

A polymerizable yellow dye of the formula ##STR11## wherein R=H or CH.sub.3 ;

• R.sup.1 =H, C.sub.1 to C.sub.20 alkyl, OCH.sub.3, OC.sub.2 H.sub.5, OC.sub.3 H.sub.7, or OC.sub.4 H.sub.9 ;
• a and b independently=the integer 1 or 2;
• R.sup.2 =R.sup.1, OH, NH.sub.2, NHR.sup.5, N(R.sup.5).sub.2, SH, SR.sup.5, OR.sup.5, OSi(R.sup.5).sub.3, Si(R.sup.5).sub.3 ;
• R.sup.4 =an acyclic organic spacing group of up to 10 atoms consisting of C, H, Si, O, N, P, S, Cl, Br or F, alone or in any combination;
• X=O, NH or NR.sup.5 ;
• R.sup.5 =C.sub.1 to C.sub.10 alkyl;
• d, e, g, and h independently=an integer from 0 to 4;
• and
• c and f independently=an integer from 1 to 4.