a native of Patrae, in Achaia (Cic. Fam. 13.19
), who is commonly said to have been a physician, and to have attended Cicero's freedman Tullius Tiro during his illness at that place, B. C. 51.
This, however, is probably a mistake, as he is no where called a physician, and rather seems to be distinguished from Tiro's medical attendant, whose name was Asclapo (ibid.
16.4, 5, 9); so that altogether it is more likely that Lyso was the person with whom Tiro lodged during his illness. Cicero seems at one time to have been afraid of his not being sufficiently attentive to his guest, and advises Tiro, if necessary, to go to the house of M'. Curius (ibid.
16.4). Tiro himself, however, seems to have been quite satisfied with his care and attention; and, accordingly, when Lyso visited Rome a short time afterwards, and stayed there for about a year, he lived on the most intimate terms with Cicero, and saw him almost everyday (ibid.
13.19, 24). When Servius Sulpicius was going as proconsul to Achaia, Cicero wrote two letters to him in Lyso's favour, B. C. 47, in which he speaks of him in terms of great affection and gratitude (ibid.