Does this screw up the theory of Donna's enhanced vision? shouldn't she be able to see without a special lens? i'd think she could read microfilm. and seriously, who uses microfilm? most microfilm collections are being transferred to electronic formats these days. it's hard to find a modern library that still carries microfilm.

Well, they could get away with that using the following logic

If her power is to see things from great distance, then it's the distance which is the power, not being able to read anything she wants...

Example, there's a piece of paper with writing on a mile away, you could see it with a telescope. That's distance viewing

However, if there's a piece of black paper with dark blue writing on it you may not be able to read it, whether you had a telescope or not, because of the reduced contrast.

Therefore, she might be able to see the microfiche from a great distance, but can't read it without the lens because of how it's printed.