Vision Testing for Forklift Drivers

Would it be appropriate to test shipping dept. forklift drivers' vision as concerns arise about the employees ability to drive their forklift safely? Would we be over-stepping any ADA or employee privacy issues?. We do conduct a cursory vision test post-offer. Current employee's who wear vision correction are required to get safety Rx glasses.
Comments
Take a look at ADA regulations at 29CFR1630.10 and 1630.14.
[url]http://www.access.gpo.gov/nara/cfr/waisidx_01/29cfr1630_01.html[/url]
For more information on what you may and may not do with post-offer "medicals" and what it takes to screen individuals related to safety issues (which I assume woould be what your purpose is for having a more extnesive eye examination for indivudals who drive the forklifts) take a look at EEOC's guidance on post-offer medical examinations at:
[url]http://www.eeoc.gov/docs/preemp.html[/url]
In our plant, eliminating someone's ability to drive a forklift truck would not affect that employee's job, as driving is only part of their daily duties.