Possible Clues:

• Blot on the landscape, one visited by tourist?
• Express sadness over onset of tunnel vision
• Spectacle's modest, 50 having withdrawn
• Gun feature regularly seen in slingshots
• Frigg ultimately appears in this swirling vision
• Thin -- not large? That makes sense
• Sense drunk needs a fresh start
• Hideous thing witnessed, I'm exasperated and traumatised initially
• A great deal in view
• Spy