Ovuvite vitamins extreme fatigue??

I am hoping someone can explain the fatigue.

Long story short. Last year a doctor lied to me and said my vision was incorrect able and I needed immediate surgery. Told me I would go blind without surgery. For a year I was terrified. My prescription which she gave me was wrong but a month ago it expired so I went to new doctor. He prescribed ocuvite and told me the disease would reverse itself.

I have been taking the Areds2 and they work. My vision is much much brighter. Very happy.

But
I take two and they make me incredibly sleepy. I pass out for two hours and it takes me ten minutes or so to really wake up.

Why would vitamins make me so sleepy?