Transient astronomy and the quest for short-duration events is under a revolution. Since the early 2000s thousands of radio transients have been discovered, renewing the interests in long wavelength observations but now at a high cadence, >~ 1 ms. Events such as pulsar glitches (Wang+2012), giant pulses (GPs), nano-shots (Hankis+2016), have been observed frequently in the past, but now newer events such as fast radio bursts (FRBs; repeating and non-repeating; Petroff+2022), rotating radio transients (RRATs), millisecond pulsars (MSP), and persistent radio sources (PRS) have revolutionized the field, mainly because of their unknown nature and poorly constrained astrophysical mechanism. Further, newer and upgraded radio facilities will be able to localize within less than 100 mas (Cassanelli+2023; Sanghavi+2023; Cassanelli+2022b; Mena-Parra+2022; Leung+2021) such events, opening the window for precise follow-up observations for optical counterparts and afterglows. In this talk I will discuss efforts to follow-up these sources in the optical regime, using a fast photon counter, the Italian quantum eye (Iqueye), combined with Gemini South (as a visitor instrument). I will present the state-of-the-art of fast optical transients, our instrument and team, efforts to deploy the instrument at Gemini South, and specific science cases for our proposed experiment.