Reprint from THE OPTICAL JOURNAL AND REVIEW OF OPTOMETRY
|Vol. XXXVII||New York June 8, 1916||No. 24|
From a logical point of view it would seem that a pair of large plano goggles could protect a person's eyes from the dust more than would a pair of 00[*] size-eye lenses in plus 1.00 spectacles. This would be true were there no relationships between dust and focus. that such a relationship existed I knew soon after I began the practicing of optometry, but for years afterwards I was unable to grasp what the relationship was.
If a driver (not a chauffeur)[†] comes to you for glasses to protect his eyes from the dust, and if you take the trouble and have them examined, you will invariably find a considerable amount of defect. If you ever watch a gang of threshers in the country you are likely to come across a fellow who will be busy rubbing his eyes while his companions are usy working, and if you succeed in having them examined, you will here also find an error of refraction. If you take a walk with a companion on a windy day where there is dust or smoke and the eyes of your companion become filled with it, you can be perfectly satisfied that there is an ametrope (defective eyes) walking beside you and the retinoscope and trial-case will prove it.
Evidences were not lacking to prove above statements as facts, but why? Why should the inanimated dust, chaff, and soot be attracted more into the eyes of ametropes (defective-eyes) than into the eyes of emmetropes (normal-eyes). What was the reltionship? At last it dawned upon me and here it is.
There is a relationship between the agencies of refraction and filtration of the eyes. A normal eye will, as arule, have a normal system of filtration while the filtration system of the abnormal eye will be abnormal. he normal discharge that moistens the emmetropic (normal) eye is as thin, or thinner than, water, while the discharge that covers the strained ametropic (defective) eye is thickned. It is gluish.
The tiny particles that are driven into an emmetropic (normal) eye by the force of the wind are driven out of it by the same force, and what is left behind is washed away and carried off by the moisture of the eye. The substances that come in contact with the ametropic (defective) eye stick to the gluish matter that coves it.
Focus is an antiseptic for dust.
*Old-time small size lenses -- 1 eye, 0 eye and 00 eye. Goggles were much larger.
†Chauffeur: driver of a closed carriage
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