Brian:
The Principal's Nose at TOC is really a series of three bunkers (one fronting, two side-by-side) that play a significant factor in the strategy of the tee shot at the shortish par 4 16th.
Spectacles are two bunkers side-by-side on the shortish par 5 14th at Carnoustie, and come into play on the second shot there.
At The Old Course (like many tee shots there) the decision off the tee is: play safely left and leave yourself with a tougher approach, or play the riskier shot right, and be left with an easier approach. This feature of TOC, repeated often there, is perhaps most pronounced at 16, because of the small (tiny, really) and narrow strip of fairway between the Principal's Nose and the OB right, and width of the available fairway left off the tee there. The bunkers, like many at TOC, are somewhat subdued in their appearance, and are of a gathering nature -- get a ball on a roll toward them, and they stand a good chance of going in. With today's technology, the Principal's Nose bunkers can probably be flown, but Deacon Sime -- a nasty little pot bunker -- lies hidden 30 yards beyond to catch the bold player. The Principal's Nose bunkers sit about 145 yards from the middle of the green (I don't have yardages from the tee to the bunkers from the latest Open set-up.)
Spectacles are two very large, pushed-up bunkers with high lips that sit about 65 yards from the green on the par 5 14th at Carnoustie. When re-designed by Braid, they probably played a significant factor in strategy -- take a chance of flying them with a second shot, or risk losing a stroke by putting your shot in them. They are visually intimidating, but for today's players, their chief strategy is that they make the landing area of the 2nd shot blind, but the green opening there is pretty wide and the green is quite deep, making for a fairly routine second shot for most players (in Open conditions).