Studies of the proportion of the face and the eye

These two fragments, exhibited together for the first time in 1975, are part of a single drawing that was created around 1489–90 and separated at an unknown time.

The fact that the two pieces of paper are cut from the same sheet is confirmed by the continuity of the theme and by the metalpoint geometric pattern on the front, consisting of circular arcs made with a compass and straight lines that continue from one side to the other.

The larger sheet contains several notes. Here are some of them: “a. n. o. f. are equal to the mouth—a. c. and a. f. are equal to the space between one eye and the other.”
“m. c. is 1/3 of n. m. measuring from the outer corner of the eyelids to the letter c.”
"b. s. will be equal to the width of the nostril.”

The transcription of the longest block of notes is: “n. m. o. p. q. r. are equal to half the width of the eyelids, that is from the inner corner of the eye to its outer corner; and in like manner the division between the chin and the mouth; and in the same way the narrowest part of the nose between the eyes. And these spaces, each in itself, is the 19th part of the head, n. m. is equal to the length of the eye or the space between the eye.”

On the right-hand side of the paper, da Vinci has written some calculations.

The smaller piece of paper features two pieces of information about the eye. It reads:
"The distance between the centres of the pupils of the eyes is 1/3 of the face. The space between the outer corners of the eyes, that is where the eye ends in the eye socket which contains it, thus the outer corners, is half the face. The greatest width of the face at the line of the eyes is equal to the distance from the roots of the hair in front to the parting of the lips."

Both drawings are part of the numerous studies on proportion that da Vinci carried out around 1490 and which also include the famous Vitruvian Man.

In particular, this drawing should be placed in relation to the proportional studies of the head conducted by Leonardo.