Both eyes open?

Ive been trying to teach myself to shoot with both eyes open when using my pistol. Ive researched and it just doesn’t make sense to me. I dont see double, its not blurry. I just literally cant seem to see the front side unless the gun is damn near sideways and not looking through the rear sights, or i close my left eye. Any techniques?To add. If i close my non dominant eye for a second and open i can get clear sight picture with both eyes but within 3 seconds i lose it. Even if im staying still via /r/CCW https://ift.tt/3rHkmzF