Do Christians pray to icons and sculptures?

Answer: In its fourths part of its explanation of the first of the "Ten Commandments” the Catechism of the Catholic Church comments on the last word of the first Commandment : “You shall not make for yourself a graven image“:

2129 The divine command prohibits any representation of God by the hand of man. Deuteronomy explains: "You saw no form at all on the day the LORD spoke to you at Horeb from the midst of the fire. Be strictly on your guard, therefore, not to degrade yourselves by fashioning an idol to represent any figure, whether it be the form of a man or a woman...." (Deut 4:15-16). It is the absolutely transcendent God who revealed himself to Israel. "He is the all," but at the same time "greater is he than all his works" (Sirach [Ecclesiasticus] 43:28 (30). He is "the original source of beauty." (Wisdom 13:3).


2130 Nevertheless, already in the Old Testament, God ordained or permitted the making of images that pointed symbolically toward salvation by the incarnate Word: so it was with the bronze serpent (see Num 21:4-9; Wisdom 16:5-14; John 3:14-15) the ark of the covenant, and the cherubim (see Ex 25:10-22; 1 Kings 6:23-28; 7:23-26).
2131 Basing itself on the mystery of the incarnate Word, the seventh ecumenical council at Nicaea (787) justified against the iconoclasts of the veneration of icons - of Christ, but also of the Mother of God, the angels, and all the saints. By becoming incarnate, the Son of God introduced a new "economy" of images.

2132 The Christian veneration of images is not contrary to the first commandment which proscribes idols. Indeed, "the honor rendered to an image passes to its prototype" (St. Basil, De Spiritu Sancto 18, 45) and "whoever venerates an image venerates the person portrayed in it." (Council of Nicaea II: DS 601; Vatican Council II, Lumen Gentium, 67). The honor paid to sacred images is a "respectful veneration," not the adoration due to God alone.

"Religious worship is not directed to images in themselves, considered as mere things, but under their distinctive aspect as images leading us on to God incarnate. The movement toward the image does not terminate in it as image, but tends toward that whose image it is. (St. Thomas Aquinas, Summa Theologica 2-2, 81, 3, ad 3).

It goes without saying that in this context, the meaning of the word "image“, also, refers to icons and sculptures.