When something is declared as "truth" in the Bible it means it comes from the Lord and is true down to the deepest levels of reality.

170. Representations and Appearances in Heaven

Anyone who thinks solely from natural light cannot understand that anything in heaven is like anything in our world. This is because such people, on the basis of this light, have both thought and decided that angels are nothing but minds, and that minds are like ethereal breath. This would mean that angels did not have the senses we do, so they would not have eyes; and if they did not have eyes there would be no objects [of sight]. However, angels do have all the senses we do - far more delicate ones, in fact - and the light in which they see is far brighter than the light in which we see.

On angels being people in a most perfect form with the use of all their senses, see 73-77 above; and on light in heaven being far brighter than the light in our world, see 126-132.