Besides Limanova, a somewhat "latinized" affair, what other so called apparitions have there been in the East besides the Holy Virgin Protection in Constantinople? How do we know "apparitions" are not some form of imagination.
Very interesting question!
The Holy Protection apparitions at Constantinople are actually several in number. There have been others in Ukraine and Russia (most notably the apparition at Pochaiv during the Turkish assault on the monastery).
The vast majority of apparitions in the Orthodox East have been in conjunction with the very many miraculous and locally-venerated icons of the Most Holy Theotokos. Such apparitions actually take second place after the miracle-working icons which are themselves glorified (or canonized) and can have more than one feast-day (the Vladimir Mother of God has six or seven days, if my memory is correct), and Churches are built in their honour - just as they are in honour of Saints.
Whenever an apparition is associated with an icon, it is commemorated in the menaion "life" of the icon and may also be added to the calendar.
One example is the Feast of St Nicholas which is coming up where the popular icon of St Nicholas flanked by OLGS Jesus Christ on one side and the Most Holy Theotokos on the other (and there are several miraculous icons of St Nicholas like this depiction including that of "Nicholas the Wet") and this icon is actually a representation of the apparition experienced by the Council Fathers in 325 AD when they censured Nicholas for punching Arius in the face upon his condemnation as a heretic.
The Fathers removed Nicholas' Gospel and Bishop's mantle for behaviour unbecoming a Bishop when they saw Christ and His Mother appear on either side of Nicholas holding the very things they had just removed from him - as if to tell the Fathers to return these to Nicholas (which they did, of course).
I could be wrong, but it seems to me that the Christian East has a greater liturgical emphasis in its dealing with apparitions and icons which serve to build up the entire Church.
Alex