MAL de DEBARQUEMENT SYNDROME (MdDS)
MdDS is a neurological condition typically characterized by the sensation of motion that persists more than a month following exposure to the passive motion experienced on the water, air or land, but can also occur spontaneously. Individuals with the condition experience continuous rocking, swaying or bobbing, as well as additional symptoms, such heightened sensory sensitivity, head pressure, migraine, nausea, intolerance of crowds, brain fog, impaired cognition, blurry vision, anxiety, depression, and lethargy. 
While precision tinted lenses are not designed to treat MdDS, we have found that precision filter lenses can relieve these often-reported accompanying symptoms listed above as they may be caused by visual stress. Common visual stress symptoms include headaches and migraines, sensitivities to lights and movement (i.e., crowds), cognitive fatigue (i.e., brain fog), mis-perception (i.e., blurry vision not caused by refractive error or balance issues), anxiety and fatigue (i.e, lethargy). If visual stress was present prior to the onset of MdDS, then the symptoms may be exacerbated by the MdDS.
This overlapping of symptoms of MdDS, migraine, and visual stress would indicate the importance to rule out and treat visual stress if it is contributing to symptoms.
At Opticalm we have seen several clients with MdDS that have experienced a reduction in symptoms with their precision tinted lenses.