Health issue

I had always wanted as many kids as possible. But now I am facing a health problem, that means either I choose between having more kids and going blind or not having more and keeping my eyesight. A lot of Christian friends have stressed to me that they believe preventing kids in any way is wrong. But what am I supposed to do? It’s not like I wanted things to go this way. I’m very thankful for my one beautiful, sweet child I was able to have. Hubby and I are very open to adopting if God provides.