De praecipius visus symptomatis eorumque causis Physica & Medica contemplatio

LXXI.
Thus, indeed, whether by the accident itself or by an error of treatment, the pupil, having been moved obliquely without the disturbance of the humors up to the region of the excavated bone, was able to draw images through the nostrils and see internally, with the structure of the instrument partially safe; but concerning contingent things, hōs elachista as the least possible, the truth is not determined.

LXXII.
Let this at least be considered settled and firm, that not only for the function of any instrument, but especially for the eyes, the exact connection of parts among themselves contributes the most, and every asymmetria lack of symmetry produces error. Which the opticians demonstrate more subtly, when they posit the figure of the eye as necessarily spherical and the orbit as concentric to the perimeter of the crystalline humor and the corneal tunic, but the rhagoideōs uvea/grape-like tunic they establish as a sphere eccentric to the whole eye; but these things are outside the present task.

LXXIII.
The remaining causes of blindness from a scar of a wound obscuring the pupil, the outflow of aqueous humor, obstacles of suffusions cataracts, pterygium, etc., are manifest. Sometimes an intrinsic affection of either the nerves, or the spirits, or the humors, or the tunics, born suddenly or gradually, takes away sight as in amaurosei amaurosis/dimming of vision.