Leonardo da Vinci’s theories about floaters were influenced by the prevailing scientific and philosophical ideas of his time. In the 15th and 16th centuries, the understanding of anatomy and physiology was still largely based on the works of ancient Greek and Roman scholars, such as Galen and Aristotle.
One of the dominant theories of vision during this period was the “extramission theory,” which proposed that the eye itself emitted rays of light that interacted with the objects in the environment to create sight. According to this theory, the eye was an active participant in the visual process, rather than a passive recipient of light.
In the context of this theory, da Vinci speculated that floaters might be caused by imperfections or irregularities in the eye’s internal structures. He believed that these irregularities could interfere with the eye’s ability to emit visual rays, leading to the perception of floating specks or strands.
Da Vinci also considered the possibility that floaters were related to the presence of tiny particles or “atoms” within the eye. In his notebooks, he described floaters as “small, round, transparent particles” that moved in response to the motion of the eye. This idea was influenced by the atomic theories of ancient Greek philosophers, such as Democritus, who proposed that all matter was composed of indivisible particles.