The present invention relates to method of fabricating a wafer level optical lens substrate. The method comprising providing a first wafer substrate having a plurality of bumps, applying a first polymer liquid on a first contact optical surface of said plurality of bumps, providing a second wafer substrate, and contacting said first wafer substrate with said second substrate in such that said first polymer liquid is located in a slit created between said first contact optical surface of said plurality of bumps and said second wafer substrate under capillary forces. The method comprises thereafter curing said polymer liquid(s) to form a lens.