Premium
THE EFFECT OF THE ANTERIOR AND POSTERIOR PARTS OF THE EYE ON ULTRASONIC INTENSITY
Author(s) -
OKSALA ARVO
Publication year - 1975
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.1975.tb01137.x
Subject(s) - sclera , ball (mathematics) , materials science , acoustic shadow , sound intensity , optics , ultrasonic sensor , ultrasound , anatomy , intensity (physics) , acoustics , geometry , physics , sound (geography) , mathematics , ophthalmology , medicine
The effect of the anterior and posterior parts of a pig eye and the halves of a plastic ball on relative sound intensities was examined using a steel ball, with a diameter of 2 mm, as the reflector. Six acoustic cross sections of the halves of the pig eyes were examined. Intensity measurements were performed 1 mm from one another in each acoustic section. The lens caused a round, relative acoustic shadow, with a diameter of 5–7 mm, which attenuated ultrasound up to 15–20 dB. The sclera caused, 3–4 mm from the edges, either an absolute or an almost absolute shadow, which was circular in shape and had a diameter of 1–2 mm. The edges of the sclera caused a slight increase in sound intensity, which was probably due to their focusing effect. A narrow, circular acoustic shadow, similar in shape to the above‐mentioned, but relative, was found when the effect of the halves of the plastic ball was examined. The edges of the halves of the plastic ball did not have any focusing effect.