Encandilar means 'to dazzle' or 'to blind with light'. It's a vivid and somewhat less common verb that paints a strong image.
In the song, the lyrics mention, "mis ojos se marchitan... que reflejó hasta encandilar" (my eyes wither... that it reflected until it dazzled). This suggests the intensity of the singer's emotions or the beloved's presence is so strong it's almost blinding, adding a dramatic flair to the expression of longing and love.
Darío Gómez's "Donde Estas Corazón" is a heartfelt plea from someone deeply in love and missing their beloved. The singer can't imagine life without this person, asking "dónde estás corazón que no puedo ya vivir sin ti" [where are you, my heart, that I can no longer live without you?]. He remembers meeting them at a party and how wonderful it felt to fall in love, wanting to feel them in his life: "qué bonito es amar y en mi vida te quiero sentir" [how beautiful it is to love, and I want to feel you in my life].
This song really gets to you with its raw emotion. The singer describes how much this absence is affecting him, saying "si vieras como me tienes ya mis ojos se marchita" [if you saw how you have me, my eyes are already wilting]. He's so desperate to see them again, offering his whole life: "te quiero dar corazón mi vida para que no vivas tan lejos de mí" [I want to give you, my heart, my life so you don't live so far from me]. It's a powerful expression of longing and devotion, making you feel every bit of his yearning.