Here’s a neurological oddity to be aware of: Transient smartphone blindness. Per a case report in this week’s Green Journal:
When a patient lies on one side, the ipsilateral (lowermost) eye becomes functionally occluded (e.g., by a pillow) and its retina maintains adaptation to the ambient light level or may become relatively dark-adapted. Meanwhile, the contralateral (uppermost) eye becomes light-adapted while it is used to view the device, which illuminates the retina to a greater degree than ambient light (this differentiates the scenario from book reading). After the patient stops using the device and transitions to binocular vision with both retinae exposed to dim ambient light, she perceives normal vision with the dark-adapted eye but temporary blindness in the light-adapted eye.
It’s easy to see how this could be misdiagnosed as a retinal TIA, retinal migraine, functional disorder, or even MS as per the case report.