To convert a foreign license, you will be required to pass a vision test and a written knowledge test, with a valid, unexpired, foreign license you may not be required to take the road skills test. Only foreign license that the DMV can authenticate will be accepted.
You can apply to exchange your licence online or in person at a National Driving Licencing Service (NDLS) centre. You may need to include a medical report with your application. The NDLS has information on when a medical report is needed.
If you have a valid driver's license from another state or country, you may use it to drive in Illinois throughout your stay (if you do not plan to become a permanent resident of this state). Illinois does not recognize the international driver's license.