Composition for manufacturing contact lenses

A composition for manufacturing contact lenses comprising:

• a first siloxane macromer with the number average molecular weight in a range of 500 to 10,000, represented by the following formula (I)
• wherein in formula (I), R1, R2 and R3 are independently C1-C4 alkyl groups, R4 is C1-C6alkyl group, R5 is C1-C4 alkylene group, R6 is —OR7O— or —NH—, R7, R8 are independently C1-C4 alkylene groups, m is an integer of 1 to 2 and n is an integer of 4 to 80;
• a second siloxane macromer, with the number average molecular weight in a range of 1,000 to 10,000, represented by the following formula (II)
• wherein in formula (II), R9, R10 and R11 are independently C1-C4 alkyl groups, R12, R13 R15, are independently C1-C3alkylene groups, R14 is a residue obtained by removing NCO group from an aliphatic or aromatic diisocyanate, o is an integer of 4 to 80, p is an integer of 0 to 1 and q is an integer of 1 to 20;
• at least one hydrophilic monomer;
• an initiator;
• and
• a crosslinking agent;
• wherein the first siloxane macromer of formula (1) is present at an amount of 20 to 45 parts by weight, the second siloxane macromer of formula (II) is present at an amount of 3 to 30 parts by weight, the hydrophilic monomer is present at an amount of 30 to 55 parts by weight, the initiator is present at an amount of 0.1 to 1.0 parts by weight and the crosslinking agent is present at an amount of 0.1 to 5.0 parts by weight based on the total amount of the composition.