“…The direct-acting cholinergic drug can alter lens permeability, leading to a shift in lens cations and water accumulation, causing changes in the intraocular metabolism and its use may accelerate lens opacities formation. [ 2 ] Hence, the long-term adverse effect of the drug should be kept in mind. Pilocarpine binds to melanin in the iris and ciliary body and hence, iris color may influence its desired response.…”