discovering a hidden item by "looking down"

Im trying to figure out a way to be in a room where an object is hidden ( not in the room description ) unless the player “looks down” … any guidance would be greatly appreciated

Have the object off-stage at start of play (that is, create it, but don’t place it anywhere). Then move it to the room when the player looks down, perhaps with an “instead of examining down” rule.

Dim Cave is a room. "There is just enough light to make out the walls of the rocky passage[if the ring is off-stage]. Out of the corner 
of your eye you catch a glint from something on the cave floor nearby[end if]." 

The ring is a thing.
Instead of examining down in Dim Cave when the ring is off-stage:
      say "You are surprised to see a golden ring lying against a rock.";
      move the ring to the location.

Note that “look down” is not a common command in interactive fiction, and experienced players might not think to try it unless you give them a fairly broad hint.

worked like a charm , JRB ! thanks so much

Yeah, seconding the issue that the player might not know to “look down”. Are you figuring you’ll also move the ring to the location when the player types “x something”, “x glint”, etc.?