In newer studies, it is now being proven that the wrong use of smartphone devices at bedtime, in the darkness may be responsible for loss of vision.Transient smartphone blindness (TSB) is a real occurrence and may contribute to a neurologic misdiagnosis in clinical practice with patients experiencing this condition reporting temporary, painless loss of vision in one eye after using a smartphone while lying on one side in bed.

These patients may initially receive a false diagnosis of a neurological condition like multiple sclerosis (MS) and may be wrongly advised to start a disease-modifying treatment. This may also result in unnecessary investigations and therapy.Medscape Medical News reports that with the ever-increasing use of smartphones, cases of TSB are likely to grow, so it's important for clinicians to enquire as to when and where the problems with vision occurred. This phenomenon is certainly unusual. It's not known if it's underreported by patients or under-recognised by physicians. 

Regardless, if you complain of loss of vision in one eye, getting the complete picture is important.

What causes Transient Smartphone Blindness

TSB symptoms are caused by "temporarily discrepancy in light adaptation levels between the retinae in the two eyes. The use of the smartphone, body position, and amount of ambient light may provide important clues to smartphone related blindness.

In a case report, a patient had laid on the  left side in bed after awakening in the early morning hours and used the smartphone for approximately 10 to 15 minutes. No light other than what was provided by the phone was used.Once the patient stood up, the vision in the right eye suddenly blacked out for about 15 seconds and then returned within a minute later. There was no report of any pain, accompanying neurological or orthostatic symptoms. The patient had no history of migraine, ophthalmologic disorders, or cerebrovascular risk factors.The patient’s visual acuity and other ophthalmologic tests were negative and both cardiovascular and neurologic exams showed nothing abnormal. Although the Brain MRI showed some bilateral cerebral white matter lesions, cervical and spine MRIs (as well as cerebrospinal fluid and metabolic/inflammatory disorders) were normal. This patient was diagnosed as having Multiple Sclerosis by her neurologist.At the 6-month follow-up, another brain MRI showed no changes and, after showing normal head and neck magnetic resonance angiography, TSB was finally diagnosed.

Understanding TSB

Reports show that symptoms related to TSB develop within minutes after viewing a smartphone screen while lying in bed in the darkness.Further investigations revealed that sufferers typically looked at their phones with only one eye while resting on their side and that their other eye was covered by a pillow.The experts explain that while one eye got adapted to the dark, the other became used to the bright light from the phone's screen.When the patient used both eyes again, the one that had been staring at the screen was unable to cope with the darkness, leading to the sensation of a loss of vision.

This situation was replicated by researchers by looking at their smartphones in the dark with only one eye and found it took their eyes several minutes to recover.The experts say that as smartphones are increasingly being manufactured with brighter screens and are used day and night, this phenomenon is likely to become more common. 

Presently, this condition appears to be transient, benign and self limiting in condition however long term consequences may be further understood as more cases are reported and studied worldwide.

So, if you are one of those who enjoys reading your Facebook page or viewing the latest Instagram posts while lying down in the dark at bedtime, you may want to reconsider.