  In this work the processes of absorption charge-exchange and
photo-association in He+H$^{+}$ collisions together with the process of ion
HeH$^{+}$ photo-dissociation are considered as factors of influence on the
opacity of the atmospheres of helium-rich white dwarfs in the far UV and EUV
region. It is shown that they should be taken into account even in the cases of
the atmospheres of white dwarfs with H:He =$10^{-5}$. Than, it is established
that in the cases of white dwarfs with H:He $\gtrsim 10^{-4}$, particulary when
H:He $\approx 10^{-3}$, these processes have to be included \emph{ab initio} in
the corresponding models of their atmospheres, since in the far UV and EUV
region they become dominant with respect to the known symmetric ion-atom
absorption processes.
