
Thomas Harriot observed sunspots in 1610 but did not publish his work. In 1612 Harriot recorded that after having viewed the sun, his sight was “dim for an hour”. Oxford University astronomer John Greaves is quoted as stating that after sun observations, he would see afterimages which looked like a flock of crows within his field of vision. Sir Isaac Newton attempted to look at the sun in a mirror, which blinded him for 3 days and caused him to experience afterimages for months








