Protective shades are round it for the guests (8)
I believe the answer is:
visitors
'the guests' is the definition.
(I've seen this before)
'protective shades are round it' is the wordplay.
'protective shades' becomes 'visors' (visors protect the eyes).
'are round' indicates putting letters inside.
'visors' placed around 'it' is 'VISITORS'.
'for' acts as a link.
(Other definitions for visitors that I've seen before include "'Callers, guests (8)'" , "Callers or tourists" , "Holiday-makers or guests" , "They call socially or on business" , "They come to call, or holiday makers" .)