Migraine with Visual Aura: This condition is characterized by transient visual symptoms, including blurred vision, blind spots, or a whiteout, often preceding a headache. The duration of 30 minutes fits within the typical timeframe for a migraine aura.

Ocular Migraine: Similar to migraine with visual aura but without the headache, ocular migraines can cause temporary visual disturbances, including bilateral vision turning white.
Transient Ischemic Attack (TIA): Although less common, TIAs can cause sudden, temporary visual disturbances, including bilateral vision loss or whiteout, due to transient cerebral ischemia.
Vasovagal Syncope: A reflex of the involuntary nervous system, vasovagal syncope can lead to transient visual symptoms, including graying or whitening of vision, often preceding a faint.

Stroke: Although less likely given the transient and bilateral nature of the symptoms, a stroke must be considered, especially if there are other neurological deficits or risk factors. Prompt recognition is crucial for timely intervention.
Retinal Detachment: Sudden, painless loss of vision, which could be described as vision turning white, requires immediate medical attention to preserve vision.
Acute Angle-Closure Glaucoma: This is an ocular emergency that can cause sudden, severe visual disturbances, including blurred vision or seeing halos around lights, often accompanied by eye pain and headache.

Papilledema: Increased intracranial pressure can cause transient visual obscurations, which might be described as vision turning white, often bilateral and fleeting.
Uveitis: Inflammation of the uvea can lead to a variety of visual symptoms, including transient vision disturbances, though this is less likely to cause bilateral, simultaneous whitening of vision.
Multiple Sclerosis: Optic neuritis, a common presentation of multiple sclerosis, can cause visual disturbances, including loss of vision or altered visual perception, but bilateral simultaneous onset is less typical.