UV blocking contact lens consequences?

Question

For chemistry class we're doing this project where we have to create new technology. I know that there are already contacts that block some UV rays, but our project is contacts that change into sunglass-like UV blocking lenses when exposed to sunlight. Similar to the transition glasses, only in contact form.
Does anybody have any ideas what the consequences of these lenses would be?
I can make up most of the positive ones, but I'm having a little trouble with the negatives.

Answer 1

An early problem with transition lenses was the time required for transition. Going from a brightly lit area to a dimly lit area could be hazardous during the period when you are effectively sightless. You can easily remove glasses to compensate, but contacts aren't easy to remove quickly.

Answer 2

It would be more difficult to read outside
It would be more difficult to see when coming inside and waiting for the reverse change

Ask people who have transition lenses what their negatives are.
I take my glasses off when I go inside till they change.
I also have a problem reading charts on the boat when there is not enough light let through to see the small print.