The proximity effect is a direct signature of the enhancement in the
strength of the UV radiation field nearby quasars. Typically found in
high resolution spectra and combining several lines of sight (LOS), this
effect was never detected systematically on low resolution data. This
talk will be focused on the technique used to reveal the proximity
effect along single LOS, the possibility to gain information from its
strength on cosmic variance, quasar lifetime and hydrogen distribution
surrounding the QSOs.

The second part of this talk will concentrate on numerical simulations I
am running in collaboration with Nick Gnedin, meant to provide a
valuable theoretical help in the interpretation of our observations.