We have MoH p.101 To See as Though a Plethron Distant with:
William Bonisagi theorized that the species, recreated as they are, bear insufficient connection to the things they represent to support casting spells against them. By being so far removed, the magus would essentially be attempting to cast his spells on mere apparitions.
Anyway, TSaTaPD does not allow to cast around the corner, but only to make casting Hermetic Geometry spells a little easier. So "Anything that the Magus can see" refers to his physical sight - also because "A blind magus can only affect himself."
Eyes of the Eagle, however, does not improve what a magus can see, but how. It makes the identification of targets easier for a magus, but does not add to their acquisition.
So we have pretty fine distinctions around T: Sight - which an eccentic SG might perhaps disregard.