There was a solar eclipse in February and a devotee astrologer wrote an interesting article which you may want to read:
Hmmm... I guess I can't post URLs until I've made 15 posts. Oh well.
"Tomorrow there will be a terrible eclipse of the Sun in Capricorn. As per Vedic intelligence, the vibrations of the Sun become adverse during an eclipse, so common sense dictates that especially pregnant women, mothers, children and all others should stay indoors and avoid the Sun's rays on Wed. as much as possible."
It is not Lord Vishnu who is affected by eclipses, as obviously He is the Supreme Controller. However, His devotees should take precautions, just as they do on Ekadasis (avoiding grains, etc.)