A Study to Evaluate the Effectiveness of Critical Flicker Fusion in Distinguishing Different Causes of Altered Vision


About this study

The purpose of this study is to evaluate the effectiveness of the critical flicker fusion device in distinguishing different kinds of optic neuropathy and visual perception.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Patients 4-90 years or older.
  • Patients  with visual acuity between 20/20 and 20/200.
  • New or established Patients having a diagnosis of autism ages 4-18, (n=20), enrolled through cognitive disorder clinic.
  • Patients ages 4-90, (n=110) with optic neuritis, compressive optic neuropathy, ischemic optic neuropathy, and traumatic optic neuropathy, enrolled through ophthalmology.

Exclusion Criteria: 

  • Subjects with high standard deviation on the testing, which indicates unreliable results.      
  • Subjects with a history of photosensitivity or history of photosensitivity resulting in seizures.
    • Note that since all tests performed in ophthalmology involve lights and are used on a daily basis in ophthalmology in patients with a history of seizures, only patients with a history of seizures induced by lights will be automatically excluded. 
  • Patients who are not light sensitive with a seizure disorder will be invited to participate.


Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Cheryl Khanna, M.D.

Open for enrollment

Contact information:

Sepideh Jamali Dogahe M.D.

(507) 293-1807


More information


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