"Whether led by reason or by desire alone, no human being does anything except in accordance with the laws and rules of nature." Spinoza
Nothing can conceivably act contra naturam, as Spinoza proclaims in Chapter vi "on Miracles" of the Theological-Political Treatise. There is no distinction between art and nature.
Spinoza is not intervening in Nature through an act of will to produce lenses contra naturam. Spinoza, his lathe, and the manufactured lenses behave strictly and solely according to the Laws of Nature expressed through his and their essence.