  We present a study of photochemical hazes of exoplanet atmospheres based on a
self-consistent model including haze microphysics, disequilibrium chemistry,
and radiative feedbacks. We derive the haze properties required to match HST
observations of ten hot-Jupiters. HAT-P-12b, HD-189733b, HD-209458b and WASP-6b
require haze mass fluxes between 5x10$^{-15}$ and 9x10$^{-12} g.cm^{-2}.s^{-1}$
to match the observations. WASP-12b and WASP-19b with equilibrium temperatures
above 2000 K are incompatible with the presence of haze and are better fitted
by heavy metals. HAT-P-1b and WASP-31b do not show clear evidence for the
presence of hazes with upper mass fluxes of 10$^{-15}$ and
10$^{-16}g.cm^{-2}.s^{-1}$, respectively, while WASP-17b and WASP-39b present
an upper mass flux limit of 10$^{-16} g.cm^{-2}.s^{-1}$. We discuss the
implications of the self-consistent model and we derive upper limits for the
haze abundances based on photochemistry results. Our results suggest HCN as the
main haze precursor up to 1300 K effective temperatures and CO above. Our
derived haze mass fluxes based on the fit to the observations are consistent
with the photochemistry with formation yields up to $\sim$6.4\%. Disequilibrium
chemistry has negligible impact on the spectra considering the low resolution
observations used but impacts the chemical composition and temperature
profiles. We find that hazes produce hotter upper atmosphere temperatures with
a detectable impact on the spectra. Clouds may have implications for
interpreting the transit spectra of HD-209458b, WASP-31b and WASP-39b.
Nevertheless, the presence of silicate and iron clouds is expected in all
studied atmospheres except WASP-12b and WASP-19b.

Earth and Planetary Astrophysics