Twinkle Eye Ponies
"Twinkle Eye Ponies" were one of Hasbro's 'gimmick' sets for this year. They were obviously popular, as there were two following sets in 1986 and 1987. Combining the idea of multicoloured manes and tails with a new idea, each Twinkle Eye Pony was distinguishable by the jewels they had for eyes. (Sometimes this gave them a chameleonic look!)
In the UK, these hit the shelves probably in very late 1985, but were a full blown part of the 1986 line and promoted on the 1986 insert. They were also available in the store catalogues for shops like Argos in 1986, where they were promoted as having "dazzling" twinkle eyes and retailed for £3.65 (probable retail price was between £3.65 and £3.99 that year).
GALAXY in the 1986 Argos Catalogue (UK)
It;s worth mentioning that all of the Generation 2 ponies had gems in their eyes, but none of these are actual "Twinkle Eye" ponies!
The first set included two unicorns, two pegasi and two earth ponies. It also saw the very first parting of the ways where UK and US naming was concerned - Sweetie was known as "Sweet Stuff" in North America. But, this is a UK website - so from hereon in she will be referred to as "Sweetie" :)
The Twinkle Eyes were introduced to kiddies in the UK via a story in one of the comics - edition eleven -where they were enslaved by the Jewel Wizard in a mine called the Cave of Jewels, blinded by the constant darkness. Applejack unwittingly stumbles upon their plight. Then, upon their escape, the jewel throne of their captor broke into several pieces (no prizes for guessing which little pony was responsible for THAT happening), becoming the gemstones that gave them back their sight. (Thanks to Lady Guinevere for this anecdote, which I have confirmed is a story in issue 11!). That's pretty intense stuff for a kid's comic!
It's also worth mentioning that Hasbro got themselves a bit confused with this set. It's believed there are a batch of these out there (certainly I've seen a few) with adult Twinkle Eye Ponies sealed on UK Pearly Baby Sea Pony cards. There are also several surviving MOC from this set where the pony is sealed on a card with the wrong name and story.
Oh well - I guess you can't get everything right first time!
You can find some photo examples of these on individual pony pages.