[Vision measurement in candelas: description of a psychophysical technique to quantify luminous intensity].

Purpose: To develop a method and a device for vision measurement in candela (cd). Vision measurement studies are important to all visual sciences.

Methods: It is a theoretical and experimental study.

[Vision measurement and psychophysical tests].

Vision measurement is the basis for the study and standardization of visual sciences. Measurement of visual acuity has great value for research and for clinical practice. This paper (1) reviews the fundamental concepts to understand visual sense and the measuring units; (2) presents the fundamental limits to visual performance and the principles of aberration measurement of the eye; and (3) discusses methods for measuring and classifying vision with new technologies.

[Comparative study of the biometric measurements made by immersion and contact techniques].

Purpose: To compare clinical biometric findings between measurements of immersion technique and contact technique.

Methods: Axial length was measured by A-scan in 120 medical examinations in 60 patients with cataract using a non-contact (immersion) and a contact technique in paired-samples by ultrasound.

Results: The mean axial length was found to be 23.