Vishnu sahasranamam, slok94

Slok94:        VihAyasagathirjyothihi  Suruchir  Huthabhuk Vibhuhu
                       Ravi rvirochanaha Suryaha Savithaa Ravilochanaha

The one who roams flying, the Final abode, the devine Light,  the Digestive fire of good food eaten, ( Veiswaanaro ), the Glorious one, the  bewitching celestial Wonder-Sun, the Sun, the Brillience in Sun, and the one with Sun as an eye, is sree Maha Vishnu.

In this slok,  VISHNU's presence as Sun, is emphasysed. The bewitching
Brillience of VISHNU kshetra is reflected in Sun. That's why, we consider Sun,
not just like a planet, but as a spell of Vishnu. So Sun is  very auspescious, that's  why we call by the name Surya NArAyaNa. The Radiation of Vishnu is present in Sun. 
The Magnetic Radiation of Sun, consists multiple waves of different energy forms. Many fundamrntal particals and primary gasses exist in the
Sun Atmosphere. They help for the prosperity and  growth  of earth and earthly beings. Sun has the spark of Vishnu. It is the " VISIBLE VISHNU. " "VISIBLE GOD".

SUN is an eye of Vishnu interprets Sun,as the" Universal witness."
"A SarvasAkshi". Watches everything happening everywhere.

It is said in Bhagavad Gita, "VeiswAnara"  the digestive fire, burns the food eaten.. This VeiswAnara is the disposition of Vishnu, present in us. Ofcourse,
there are many more dispositions of lord present in us. They are five elements, mind, intelligence, memory, ego, forgetfulness, chaitanya, life force, (jeva), and etc etc etc. Vishnu's glories are innumerable. Difficult to describe.

Once again,  in this slok, VISHNU is described as Resplendent Devine Light.

                           Om Vishnave namaha