We demonstrate the utility of nonplanar building blocks to tune the polymer photoelastic birefringence and obtain near zero and negative photoelastic coefficients. Photoelastic properties of two novel random copolymers systems: 2-vinlypyridene (2VP)-hydroxyadmantyl methacrylate (HAMA) and vinyl pyrrollidone (VP)-isobornylacrylate (iBOA) were investigated at a function of comonomer composition. Photoelastic coefficient of the copolymers could be facilely tuned by changing the copolymer composition. In particular, we show that negative stress optic coefficient could be obtained from VP - iBOA copolymers and near zero stress optic coefficient could be obtained from 2VP-HAMA copolymers. In addition, we investigate the effect of addition of triethylene glycol (TEG) as a plasticizer on the photoelastic properties for the 2VP-HAMA copolymers. We found that addition of TEG led to a reduction in both the polymer T-g and photoelastic coefficient. Our study indicates that bulky non-planar side groups in the polymer backbone tend to induce negative photoelastic birefringence and can be utilized as important building blocks for the design of optical polymers.