The phrase "Every eye will see Him" comes out of the following passage, specifically verse 7. Let's see the context in which it is said:
Let's provide some CONTEXT in which the words "EVERY EYE WILL SEE HIM" are used.
Verse 9 John says that he is partner with the 7 churches in Asia "IN THE TRIBULATION." see my article "The Great Tribulation happened already"
Verse 10 "THE LORD'S DAY" is NOT Sunday as many supposed scholars claim but it is YHWH's day of Judgment upon Jerusalem. There are numerous lord's days or "day of the lords" in Scripture. see my article "The Day of The Lord"
**The above event, along with everything from v4-33 were to happen in that 1st century "this generation" that Christ spoke of in Matt 24:34 "Truly, I say to you, this generation will not pass away until all these things take place."
***The saints and the aints (apostate jews) saw The Son of Man Coming in the clouds of heaven with great glory and power to judge apostate Israel. The sign that Christ was in heaven, vindicated as The Messiah, God, was Jerusalem destroyed.
Behold, he is COMING WITH THE CLOUDS, and EVERY EYE WILL SEE HIM, EVEN THOSE WHO PIERCED HIM, and ALL THE TRIBES OF THE EARTH WILL WAIL ON ACCOUNT OF HIM. Even so. Amen.***Christ is coming with the clouds.
***Every eye will SEE Him, even those who pierced Him. Who pierced Yeshua? The apostate Jews crucified Christ. Acts 2:23, 36, 4:10.
***Do you noticed how this event is tied in with Matt 24:30 where all the tribes of the earth (or land) wail or mourn? Well, this Matt 24:30 happened in that 1st century "this generation" as Yeshua said. Therefore, this Revelation passage, being the same subject happened. Plus, the things within the book of Revelation are said to be near, coming soon, at hand, shortly come to pass... see my article on "The Time statements within the book of Revelation."