Human visual performance changes dramatically both across (eccentricity) and around (polar angle) the visual field. Performance is better at the fovea. decreases with eccentricity. and is better along the horizontal than vertical meridian and along the lower than the upper vertical meridian. https://www.nacrack.com/mega-pick-Legacy-Kelly-Green-Spear-Cool-Fit-Adjustable-Visor-White-quick-deal/