Not necessarily, see this guy for example: https://www.ted.com/talks/josh_silver_demos_adjustable_liquid_filled_eyeglasses https://www.ted.com/talks/josh_silver

Not necessarily, see this guy for example: https://www.ted.com/talks/josh_silver_demos_adjustable_liquid_filled_eyeglasses https://www.ted.com/talks/josh_silver_demos_adjustable_liqui... Although I'm skeptical that third world countries will have access to high tech vision correcting tablets but not eyeglasses.