The quote also makes references to Christ and his miracles of healing the blind.  When Love "repairs" (or is drawn to) Silvia's eye, the Love, being blind, is in need of healing and restoration.  Silvia helps or cures the blindness, and then Love stays where it has been healed.  Christ's miracles of healing the blind were described to have just this effect. Before the healing, the person was without God.  But after the miracle, the person was converted and understood that God had wrought a miracle upon them.

This song has been arranged by Turio and Proteus, two gentlemen in love with Silvia, to be sung under her window.  The lyrics allude to comparsion with Christ in the stanza you mention  as a continuation of the "holy" theme mentioned in the stanza above.  The basic Christian understanding of Love, that it heals and transforms, is connected here to Silvia.

In Two Gentlemen of Verona, in the song "Who is Sylvia?" the words "Love doth to her eyes repair, To help him of his blindness; And, being help'd, inhabits there" speak of Sylvia's eyes.

The song first tells the listener that men flock to be with Sylvia: she is "holy, fair and wise."  Heaven has given her grace so she would be greatly admired.

For the line in question, the word "repair" does not necessarily mean "to fix," but in a more archaic association, it may mean that love"goes to her eyes frequently," as one might "repair to the country."

With this in mind, love goes to Sylvia's eyes; "To help him of his blindness" may refer to Cupid, who is often "painted blind."

So Love finds Sylvia's eyes to be helped in his blindness, but finds it so wonderful there, that Love (Cupid) decides that instead of moving on, he will stay there in her eyes, doting on her much the same way as the "swains" (young men) do.