Related Experiment Video
Updated: Feb 13, 2026

Eye Tracking During Visually Situated Language Comprehension: Flexibility and Limitations in Uncovering Visual Context Effects
Published on: November 30, 2018
Closed-Eye Visualizations in the Setting of Hyponatremia
Travis Peck1, Christopher Mercogliano1, Eugene York1
1Department of Internal Medicine, Reading Health System, Reading, PA, USA.
Purpose:
To report a case of closed-eye visualizations and to clarify the different types of hallucinations and their etiologies.
Methods:
Retrospective case report of a patient with closed-eye visualizations secondary to hyponatremia. Clinical findings, physical exam, laboratory assessment, treatment, and disease course from the patient's hospitalization were used in creating this report. Follow-up data after discharge were also obtained.
Results:
Closed-eye visualizations were diagnosed as secondary to hyponatremia, as they did not occur with the eyes open, and potential alternate causes were excluded. Serum sodium nadir was 119 mEq/L. Symptoms resolved with correction of hyponatremia via fluid resuscitation and electrolyte replenishment. There has been no recurrence of the symptoms.
Conclusion:
This patient had hallucinations exclusively with the eyes closed, which must be differentiated from the release hallucinations seen with the eyes open in Charles Bonnet syndrome. This patient had no visual loss or retinal disease, which should be suspected in open eye hallucinations.
Related Concept Videos
Close Relationships and Culture
Setting Time of Cement
Friendships and Close Friendships
Open and closed-loop control systems
An open-loop control system operates without feedback from the output. It consists of two primary elements: the controller and the controlled process. The controller receives an input signal...
Specialized Care Centers and Settings-II
Rural health centers are specialized care facilities in remote locations with very few medical personnel. The primary care providers who run the centers are mostly Registered Nurse Practitioners. Here, emergency treatment is provided to critically ill or injured patients before they are transferred to the closest hospital. Fortunately, due to advancement in technology, many rural healthcare facilities and professionals have easy access to diagnostic and treatment...
PPE Use in Healthcare Settings I: Donning

