What is it? Game 4.

it's what Batman used to defeat Mothman in episode...ok, i really have no clue, a hypnopaddle?

Signal device for a railroad worker

A device held by a friend to help (gun or bow) shooters to focus on where to shoot.

Its gotta be a toy! Toss the ball in the air and try to catch it in the hole. Or else bat it to someone with another of these, trying to hit their hole.

Hypnopaddle? Yeah, it does look like it, but no - this is a real device (antique).

a wee magnifying glass for starting fires with sunlight. the black rings help you focus on your mild-mannered task.

Something used for ironing? To press shirts with...

Sylvain was close. It's used on a target range. It's a paddle that's held up in front of a target to show where the last shots fired hit. At least that's what we used them for in the Army.

Nope, not used on a target range or for shooting or anything like that.

"Maki maki maki maki"
For all those Mai Otome fans.

Its a game where a ball is set on top of the circle and you have to try to balance it to stop in the center hole.

Hmm... is it a disk that you pin samples of fabrics to and then spin to see if they harmonise or not?

sort of a hand held dart board? they had to play real careful in yhose days. LOL

an optometrists' device for checking peripheral vision.

Ooh, this is a hard one. It's not a toy. And Mark, very close... (technically, you're right, but it's for a very specific porpose/condition).

I've been laughing at some of the "creative" guesses here, my favorite is the fabric harmonizer!

A glaucoma test. You tell the Optometrist/Opthamologist how many rings you can see.

That's one of the Mesmer's murderous hypnotic dazzle-truncheons. This one was thought to be lost when Mesmer's malicious minions were defeated atop the Chase Manhattan HQ in New York some 6 summers back. I thought this one was lost when the Spellbinding Spook lost his balance in the fray and fell 60 sickening stories to the asphalt below. This is the one he held in his right hand; the one for his left hand is in my Trophy Grotto deep under the East Pole in the Himalayas.

It's about 36 inches long and it is surprisingly heavy, weighing 18 pounds. I'd like to have it to complete my souvenir collection of my daring exploits, so if you're the owner, please email me of fire a Hercules flare on a clear night no matter where you live (don't worry, the autosentries on the Sattelite of Secrecy will see it) and I'll make a generous offer to you.

Dr. H.

That should be OR fire a Hercules flare, not OF fire a flare. Nano machines were battling me for control of my K-Pro keyboard, so although it is a typo it is not a mistake. I do not make mistakes.

Dr. H.

Placido’s disc for Astigmatism
http://pzphotosan148-a1.blogspot.com

Nonya's right - it's placido's disc for astigmatism (but that's from the answer posted on what is it? blog ...)

I suppose Mark (#14) is the earliest to guess the function (before the answer was posted).