Nematic liquid crystals (NLC) consist of anisotropic cigar-shaped molecules which, aligned by inter-molecular forces, macroscopically behave as a positive uniaxial with an angle-dependent refractive index for extraordinary eigenwaves. Intense electric fields can therefore induce molecular reorientation towards the field vector through dipolar interaction. Such reorientation in NLC is responsible for both electro-optic and nonlinear non local responses, the latter support ing stable two-dimensional solitons.