(Thio) (meth) acrylate monomers, intermediate compounds for the synthesis of these monomers, polymerisable compositions and polymers obtained, and their optical and ophthalmic uses

Monomer compound, characterized in that it corresponds to the formula:

• in which Z represents H or CH3 and X represents O or S, and
• when X represents S, Y is a radical of formula:
• where R1 and R2 are chosen from H, alkyl radicals, or alternatively R1 and R2 together form a —(CH2)5— radical and n1 is an integer from 0 to 2 inclusive, and
• when X represents O, Y is the radical (a) defined above or a radical chosen from the radicals of formulae:
• in which n2 is an integer equal to 1 or 2, R3 represents H or an alkyl group, R4 represents H, an alkyl group or an aryl group;
• and R5 is a divalent radical chosen from the groups of the following formulae:
• in which:
• A denotes an aryl group or an alknyl group, R′ and R″ denote, independently of each other, H, an alkyl group, aryl, or R′ or R″ can be a group
• where Ra is an alkylene group, and Rb H or CH3,
• n takes the values 0 or 1 and 0≦m (integer ≦4), and
• R6 denotes H or a methyl group, and
• Cy denotes a substituted or unsubstituted aryl ring.