From the blog "WilliamL's Worthy Insights"

“…and every eye will see Him…” Part 1 Rev. 1:7 Behold, He is coming with the clouds, and every eye will see/gaze upon Him, even they who pierced Him. And all the tribes of the earth will wail because of Him. Even so, Amen. How will it be that every eye will see Jesus Christ at His Coming? What do the Scriptures tell us? According to Zech 12:10, “they who who pierced him” will include many of the living, apparently because of their continued rejection of Jesus as Messiah up to the very instant that they see him: Zech 12:10 “And I will pour on the house of David and on the inhabitants of Jerusalem the Spirit of grace and supplications; and they will look intently toward Me whom they pierced, and they will mourn over Him as one mourns over the only son, and grieve over Him as one grieves over the firstborn.” However, Matthew 26:64 says that ones who are now among the dead – those who literally caused him to be pierced – will also see him: Matt 26:63 And the high priest answered and said to Him, “I put You under oath by the living God: Tell us if You are the Christ, the Son of God!” 64 Jesus said to him, “It is as you said. Nevertheless, I say to you, hereafter you will see/gaze upon the Son of Man sitting at the right hand of the Power, and coming on the clouds of heaven.” Now, “every eye” certainly did not see Jesus ascend from the Mount of Olives. Acts 1:9-10 That event was only seen by his disciples. Therein lies a clue as to their type of vision. Here are more scriptural clues to consider: 1 John 3:2 Beloved, now we are children of God, and it has not yet been manifested what we shall be; but we know that when He shall be manifested, we shall be like Him, for we shall see Him as He is. 1 Cor. 13:12 For now we see in a mirror, dimly, but then face to face. Now I know in part, but then I shall know just as I also am known. Luke 12:2 “For there is nothing covered that will not be revealed, nor hidden that will not be known. 3 Therefore whatever you have spoken in the dark will be heard in the light...” 2 Thes. 1:7 ...when the Lord Jesus is revealed from heaven with His mighty angels... 8 ...those who do not obey the gospel of our Lord Jesus Christ... 9 ...shall be punished with everlasting destruction apo/away from the Face of the Lord and apo/away from the glory of His power, 10 when He comes, in that Day, to be glorified in His saints and to be admired among all those who believe... What I see in these passages is this: when the Lord appears, “every eye will see him.” The Greek word for “see” here is “optanomai: to gaze upon, i.e. with wide-open eyes, as at something remarkable.” (Strong's G3700) In short, everyone will be awe-struck. For those of us who love Him and have prepared ourselves for this moment, our spirits will move into His Spirit, “we shall [then] be like Him,” and be caught up to Him. But for those who have not loved Him, or have not been prepared for this sight, they will be struck with fear and shame. This is why “all the tribes of the earth will mourn/wail because of Him,” and be removed away from His Face. More on that later.