The more luminous of two equal objects appears larger
Why two close lights merge at a distance, and why images cannot meet in a single point
Leonardo states two rules of apparent size: of things equal in size and equally distant from the eye, the more luminous appears larger, and the darker appears smaller. A diagram labelled a b, c d, e n supports the claim that two luminous bodies fairly close together look united at a great distance, for two reasons: nearby the eye readily measures the gap and their images stay distinct, whereas far off the images, and even the bodies, come to touch; and at distance the pupil, earlier contracted by the lights' power, widens again, so the eye sees the thing enlarged. A right-margin note repeats that if all images converged in an angle they would meet at the indivisible mathematical point, where all species would appear united and the sense could judge no variety. Two radiant candle-lights are drawn at the upper right.
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The more luminous of two equal objects appears larger
Of things of equal size at equal distance from the eye, the more luminous appears larger; and of equal things equally removed, the darker appears smaller.
Two close lights appear united at a distance (a b, c d, e n)
Two luminous bodies fairly close appear united far off. Near the eye their separation is readily judged and their rays do not yet touch; at distance the images bring the very bodies to touch, and the pupil, freed from the lights' power, widens so the eye sees the thing enlarged.
Images cannot meet in the indivisible point
If all images converged in an angle they would meet at the mathematical point, which being indivisible would show all species united, and, being united, the sense could judge no variety.