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The top image shows how the light enters the eye but is blurred and distorted. The bottom image shows how a cylindrical lens can correct astigmatism.

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Without Unite For Sight, I cannot imagine how I could possibly have seen and learned so much as an undergraduate about medicine, other cultures, and my own desire and ability to make a difference in others' lives.
”
—Charlotte Hogan, Unite For Sight Volunteer in Ghana and India