Respected sir,when i go to market or in crowd or when studies or when i use to talk for longer period concentrating on their talks or when i visualise things with concentration i feel the problem of vertigo,nausea,vomiting,headache and lack of concentration,,,,,,sir i checked up my eyes and i hve 175 degree cylinder with -.25 number specs...but when i take my glass off it all began to start again,i feel lot worse condition than before please help me sir