Leonardo DaVinci's concept of neutralizing the cornea included the use of what substance?

Leonardo DaVinci's concept of neutralizing the cornea involved the use of water. He envisioned that a lens could be formed by filling a cavity containing water, which would allow for the manipulation of light as it passed through, thus neutralizing the cornea's optical effects. This idea was a precursor to modern contact lenses, as DaVinci anticipated that a fluid-filled structure could aid in vision correction.

Water, being a transparent and refractive medium, was theorized to alter how light interacted with the eye, providing a foundation for visual clarity. This approach highlights DaVinci's innovative thinking about optics and his early exploration of the principles that would eventually lead to the development of corrective lenses and contact lenses.