Short interference RNAs (siRNA) are small molecules of double-stranded RNA of around 21 base pair long that specifically downregulate the expression of a target gene. This post-transcriptional mechanism of gene expression regulation has been thoroughly used to study gene function. SiRNAs exert their function in the cytoplasm of the cell, where they recognize complementary messenger RNAs (mRNA) and promote their degradation, thus blocking the synthesis of specific proteins. siRNAs can be exogenously introduced to mimic the action of endogenous RNAi triggers. Among the benefits of RNAi is the possibility of transiently silencing any given gene at any stage of development and to affect gene expression in specific anatomical regions without affecting non-targeted regions. These benefits are being used as a basis to develop a new class of innovative drugs that will most likely reach the market in 2018. Here we will outline the advances made in RNAi therapeutics in the field of ophthalmology, and in particular the developmental pathway taken by Sylentis from discovery to phase III. A compound named SYL136001v10, for the treatment of angiogenic diseases of the eye will be used as a model compound to show the potential of this new class of compounds.