Isn't wonderful how much free information you can get on the Internets(tm)? Here, for instance, is the obscure page that answers two questions that millions of readers have asked:
The question is, I think, easier to figure out than that for 42. Here, anyway, is proper credit.
In fact, three questions are answered:
. Yes, you will be able to speak of van Leeuwenhoek without sounding like an idiot.
. No, there is no uniform pronunciation from one end of the kingdom to the other; pronunciations vary no less than that of, say, Shakespeare does when you cross the Pond.
. No, you will never never be able to speak of Huygens recognizably no matter how many times you listen to the file.