  A study of eccentricity ($\varepsilon_{n}$) fluctuations and its possible
impact on final state momentum anisotropy ($v_{n}$) for symmetric collisions
are presented in the framework of Glauber model. Effect of fluctuations of
nucleon's position on the initial geometry has been studied using a new method,
where the difference between oppositely moving spectators is taken as a
measurement of eccentricity fluctuations. This study shows that higher
harmonics ($n$ =3, 4 and 5) of eccentricity are less sensitive to fluctuations
in transverse plane compared to the 2$^{nd}$ harmonic. Position fluctuations in
transverse plane will increase $\varepsilon_{2}$ and hence possibly $v_{2}$ for
the most central nucleus-nucleus collisions. For semi-central and peripheral
collisions, the fluctuations have opposite effect, it deceases the eccentricity
$\varepsilon_{2}$. The fluctuation of initial geometry can be studied in
collider experiments by studying the spectator distribution on the both sides
of the beam.
