In this drawing Leonardo uses a middle ground and saved the lightest value for the highlights.
Below are some examples of work from my students, who are visually impaired. A couple of them had to sit very close to the still life; others, had to take a picture to print or view on an iPad just a few inches from their face.
Here is the work of a student with even less vision. There are no specifics when it comes to value and fabric folds in this drawing.