So the cataract is sorrow, @Michelle .  It is sorrow itself that blinds your heart... to what?

Not love, for you address one in those terms.  Maybe, though, the realisation, the free acceptance, the confidence of it.

The temperature that consumes blinding sorrow?  The conflagration that is the very nature of the heart itself, then.  I would, philosophically, suggest the temperature of the explosion that manifested a universe of life, which prefigures the emotional fire of one's inner being.

There's another poem in there, somewhere...