Although the article doesn't mention it, there is evidence that Vermeer had access to optical devices: Antoni van Leeuwenhoek, inventor of the microscope, born

Although the article doesn't mention it, there is evidence that Vermeer had access to optical devices: Antoni van Leeuwenhoek, inventor of the microscope, born in the same year (1632) lived very close to Vermeer in Delft and was named the executor of his will, so they must have known each other well.