It is a reminder that the Sun is the physical manifestation of God, and by meditating on Him, one gains both physical health (eyesight) and spiritual wisdom (insight).
I think you meant "Surya Prashnavali" or "Surya Padhnavali" which is also known as "Solar Plexus" or "Manipura Chakra" related practices, or more likely you are referring to a practice related to Sun (Surya) in Hinduism or Yoga. surya prashnavali