Apparently there are some lyrical changes to be made to the beautiful hymn Adoro te devote. That is what Father Edward McNamara, professor of liturgy at the Regina Apostolorum university explains in Zenit.
The Adoro te devote is a Eucharistic hymn which directly refers to the Eucharistic lord. It is usually prayed or sung in the presence of the Blessed Sacrament or in thanksgiving to having received Him.
The changes are limited to the first two verses:
The first verse goes as follows: “Adóro te devóte, latens Déitas, quae sub his figúris vere látitas: tibi se cor meum totum súbicit, quia te contémplans totum déficit.” The alternative version would be: “Adóro devóte latens véritas / Te quae sub his formis vere látitas …”
And in the second verse: “Visus, tactus, gustus in te fállitur, sed audítu solo tuto créditur. Credo quidquid dixit Dei Fílius; nil hoc verbo veritátis vérius” becomes “Visus, tactus, gustus in te fállitur, sed solus audítus tute créditur. Credo quidquid dixit Dei Fílius; nihil Veritátis verbo vérius.”
Fr. McNamara goes on the explain the differences and their theological meaning, but concludes that both versions are equally valid for use. Check the piece in Zenit for his further comments.
Perhaps even more interesting to me, as a former student of English literature, is the reference to an English translation of the Adoro te devote by none other than Gerard Manley Hopkins, perhaps the most interesting Victorian poet (and a Jesuit priest). Titled Lost, All Lost In Wonder, it can be sung to the same melody as St. Thomas Aquinas’ original.
Lost, All Lost In Wonder
Godhead here in hiding, whom I do adore,
Masked by these bare shadows, shape and nothing more,
See, Lord, at thy service low lies here a heart
Lost, all lost in wonder at the God thou art.
Seeing, touching, tasting are in thee deceived:
How says trusty hearing? that shall be believed;
What God’s Son has told me, take for truth I do;
Truth himself speaks truly or there’s nothing true.
On the cross thy godhead made no sign to men,
Here thy very manhood steals from human ken:
Both are my confession, both are my belief,
And I pray the prayer of the dying thief.
I am not like Thomas, wounds I cannot see,
But can plainly call thee Lord and God as he;
Let me to a deeper faith daily nearer move,
Daily make me harder hope and dearer love.
O thou our reminder of Christ crucified,
Living Bread, the life of us for whom he died,
Lend this life to me then: feed and feast my mind,
There be thou the sweetness man was meant to find.
Bring the tender tale true of the Pelican;
Bathe me, Jesu Lord, in what thy bosom ran—
Blood whereof a single drop has power to win
All the world forgiveness of its world of sin.
Jesu, whom I look at shrouded here below,
I beseech thee send me what I thirst for so,
Some day to gaze on thee face to face in light
And be blest for ever with thy glory’s sight. Amen.
In Caelo et in Terra 
Thank for this note and the sung version. Most elucidating.