The composition for forming the transparent member, and a transparent member made of cured product

PROBLEM TO BE SOLVED : To provide a transparent member forming composition which gives a cured product having a high refractive index and a high glass transition temperature, and to provide a transparent member formed of a cured product thereof.SOLUTION : The transparent member forming composition contains a vinyl group-containing compound represented by formula (1) and a thiol group-containing compound having at least two thiol groups in one molecule. (Wand Ware each a group represented by formula (2), a group represented by formula (4), a hydroxyl group, or a (meth)acryloyloxy group; ring Yand ring Yare each an aromatic hydrocarbon ring; R is a single bond or a specific divalent group; Rand Rare each a cyano group, a halogen atom, or a monovalent hydrocarbon group; and n1 and n2 are each an integer of 0-4.)