The present invention provides a material for optical lenses which not only
sufficiently has properties such as impact resistance and dye-affinity
essential for the optical lenses but also simultaneously attains a high
refractive index, a high Abbe's number and a low specific gravity, and
which is photopolymerizable.
The present invention further provides a lens made of a synthetic resin
which is a copolymer obtained by copolymerizing a composition comprising
20 to 80% by weight of bis-2-methacryloylthioethyl sulfide represented by
the following structural formula (1), 5 to 50% by weight of a bifunctional
or multifunctional thiol and 0 to 75% by weight of a monomer
copolymerizable with these compounds, and which has a refractive index of
1.58 or more, an Abbe's number of 35 or more and a specific gravity of
1.35 or less:
CH.sub.2.dbd.C(CH.sub.3)COSCH.sub.2 CH.sub.2 SCH.sub.2 CH.sub.2
SCOC(CH.sub.3).dbd.CH.sub.2 Structural formula (1).
