  Propagation of light in the universe with structure which amplify and modify
the shape of distant galaxies, producing a correlation between nearby and
distant density of galaxies, is a phenomena very important in cosmology for
determining cosmological parameters as the {\Lambda}CDM. In this paper, we
discuss the estimation of the two point correlation function in the
gravitational shear produced by the large scale structure. We will compare the
result given by gravitational lensing with the use of another alternatives such
as a counting galaxy clusters. We also describe some software used in the
gravitational lensing study for determining mass distribution models and images
formation.
