• Technical Conference: 

    09 – 14 May 2021

  • Exhibition: 

    10 – 14 May 2021


Request CLEO Notifications

Get information about the 2022 CLEO Conference.

Registration sponsors


Thank you for attending the all-virtual CLEO Conference and Exhibition. We look forward to seeing you next year!

Policies and Terms of Registration

Reasonable policies and terms of registration have been established for CLEO. We encourage you to read these carefully as all registrants to CLEO will be required to agree to these policies and terms as a condition of registration.

Privacy Policy

CLEO and its co-sponsors respect the privacy rights of our online participants and recognize the importance of protecting all information that you may choose to share with us. To further this commitment, we have adopted this Privacy Policy to guide how we collect, store, and use the information you provide to us.



Credit cards are accepted (VISA, MasterCard and American Express). Payments made by check or wire transfer must be made payable to The Optical Society in US dollars and drawn on a US bank. Payment must accompany your registration form in order to process your registration order. 


Refund and Cancellation Policy

All requests for refunds must be received in writing by Thursday, 22 April 2021. A USD 75.00 service charge will be assessed for processing refunds. All registrations received after Thursday, 22 April 2021 are NON-REFUNDABLE. Please allow four to six weeks for processing.



CLEO 2021
c/o CompuSystems, Inc.
2651 Warrenville Rd. Suite 400
Downers Grove, IL 60515
Fax +1 708.344.4444
Registration Customer Service

For questions regarding registration, please contact the CLEO Registration Customer Service via phone or email. Customer Service hours are from 09:00 - 17:00 Central Daylight Time (CDT, UTC-5:00).

Phone: + 1 224.563.3173
email: cleo@csreg.zohodesk.com

Code of Conduct

It is important to the success of this meeting that every participant be treated with consideration and respect. Please review the Code of Conduct and Anti-harassment policy.