92 Ill. Adm. Code 442.295
Sun Visor
Section 442
Section 442.295 Sun Visor
a) The driver's side shall be equipped with an interior
adjustable sun visor with a minimum size of 5" X 16".
b) No sun visor shall interfere with the operator's full view of
the rearview mirror(s).
c) A sun visor on the right passenger side is optional.