from
The Collaborative International Dictionary of English v.0.48
Optometry \Op*tom"e*try\, n.
1. (Med.) Measurement of the range of vision, esp. by means
of the optometer.
[Webster 1913 Suppl.]
2. As defined (with minor variations) in the statutes of
various States of the United States:
(a) "The employment of subjective and objective mechanical
means to determine the accomodative and refractive
states of the eye and the scope of its function in
general."
(b) "The employment of any means, other than the use of
drugs, for the measurement of the powers of vision and
adaptation of lenses for the aid thereof."
[Webster 1913 Suppl.]