Aquae Iasae

More than one Roman town founded upon a thermal spring was
named 'Aquae Iasae'. I can't locate 'ias-' in my own Latin
dictionary, nor in two that I checked online, but surely it
is in some way connected to the Greek 'iasis' and 'iaomai',
and refers to the therapeutic effect attributed to bathing
in such springs. Is it not?

David