  In the present paper, we investigate traversable wormhole solutions
determined by an exponential shape function and fractional redshift function in
the background of four viable $f(R)$ models. Although in the absence of the
redshift function $\varphi(r)$ the null energy condition (NEC) and weak energy
condition (WEC) are violated, we find that considering the redshift function,
NEC and WEC are respected by choosing the appropriate parameters in the models.
We also investigate the conditions of stability and absence of anti-gravity
effects for these wormholes. Our results show that in the case of $\varphi(r)
\neq 0$ these conditions are satisfied easier than the case of $\varphi(r)=0$.
Finally we calculate the deflection angle using the gravitational lensing
effect. We show that the deflection angle increases by inserting the redshift
function.
