A number of recent publications on contact lenses1 seem to indicate that the interest in this fascinating subject is growing.
While particular attention is naturally given to the clinical aspect of contact lenses, especially to methods of fitting them, their optical properties2 are not always fully understood. It may not be in vain, therefore, to explain here in detail some important optical facts concerning contact lenses.
Since the understanding may be aided by considering the qualities of contact lenses in close analogy to the well known optical properties of spectacle glasses, a brief review of the fundamentals of ordinary ophthalmic lenses is offered for preliminary consideration.
In connection with an optical system two major questions are of concern: (a) Where is the image of a given object? (b) What is its magnification?
For a single spherical refracting surface, for instance, the front surface of a spherical cornea,
BOEDER P. POWER AND MAGNIFICATION PROPERTIES OF CONTACT LENSES. Arch Ophthalmol. 1938;19(1):54–67. doi:10.1001/archopht.1938.00850130066007