Composition for manufacturing contact lenses and method for manufacturing contact lenses by using the same

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-C6 alkyl 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-C3 alkylene 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;
• and
• an initiator,
• wherein the first siloxane macromer of formula (I) is present at an amount of 30 to 55 parts by weight, the second siloxane macromer of formula (II) is present at an amount of 5 to 30 parts by weight, the hydrophilic monomer is present at an amount of 25 to 60 parts by weight and the initiator is present at an amount of 0.1 to 1.0 parts by weight based on the total amount of the composition.