ABSTRACT
The effects of different luminance levels and light sources to emmetropization in the chick were investigaed. One-day-old, forty chicks were reared under condition of unilateral visual deprivation with translucent goggle. Under normal light cycles (12-h light/12-h dark), three kinds of luminance levels and two light sources (incandescent lamp vs fluorescent lamp) were used. Three weeks after hatching, refractive error, axial length, equator diameter and corneal diameter of the eyes were measured. The deprived eyes exhibited severe myopia of -11.94 diopters (p<0.001) and refractive changes were mainly related with axial elongations. Refractive error of 1000 lux group was less myopic than 2000 lux group (p<0.05). The fellow eyes didn't show significant difference between groups. No significant changes were noted between different light source groups. The experiment suggests that different degrees of illumination under normal light/dark environment can cause different refractive changes; More studies will be needed to show that the ideal luminance condition for emmetropization in our enviroment be present.
Subject(s)
Lighting , Myopia , Photoperiod , Refractive ErrorsABSTRACT
This study was performed to survey the congruities between the optical centers and pupillary centers and to bring out the optical health in Korea. One hundred outpatient were enrolled in this study, whose visual acuities were better than 20/40 with their glasses. We investigated the difference between interpupillary and interoptical center distance, the horizontal and vertical balance of optical centers, and the relation between optical decentering and dizziness. Thirty-six percent of spectacles were revealed to have inappropriate optical centers. In 25(69%) of 36 inappropriate spectacles, the difference between interpupillary distances and interoptical distances was over 4.0mm. In 7(47%) of 15 patients who complained of dizziness, optical centers were decentered. A large number of patients were wearing the optically decentered spectacles. The patients who complain of dizziness are needed to have the position of the optical centers of their spectacles checked.
Subject(s)
Humans , Dizziness , Eyeglasses , Glass , Korea , Outpatients , Visual AcuityABSTRACT
This study was performed to survey the congruities between the optical centers and pupillary centers and to bring out the optical health in Korea. One hundred outpatient were enrolled in this study, whose visual acuities were better than 20/40 with their glasses. We investigated the difference between interpupillary and interoptical center distance, the horizontal and vertical balance of optical centers, and the relation between optical decentering and dizziness. Thirty-six percent of spectacles were revealed to have inappropriate optical centers. In 25(69%) of 36 inappropriate spectacles, the difference between interpupillary distances and interoptical distances was over 4.0mm. In 7(47%) of 15 patients who complained of dizziness, optical centers were decentered. A large number of patients were wearing the optically decentered spectacles. The patients who complain of dizziness are needed to have the position of the optical centers of their spectacles checked.