Sains Malaysiana 29: 33-43 (2000)                                                                                                  Sains Hayat /

               Life Science

Effect of Body Posture on Visual Acuity, Refractive

Errorand Binocular Vision

Ai-Hong Chen & Napisah Sai

Jabatan Optometri, Fakulti Sains Kesihatan Bersekutu

Universiti Kebangsaan Malaysia

HUKM Jalan Tenteram, Bandar Tun Razak

56000 Cheras, Kuala Lumpur

ABSTRACT

The purpose of this study is to investigate the effect of the body postures on the visual acuity, refractive error and binocular vision. The near task body postures of thirty optometry students without pre-knowledge about the nature of the study were photographed from front view, side view and top view. The angles of the head tilt, body tilt and head rotation of the near task body posture for each subject were estimated based on the photographs. The habitual working distance and Harmon distance of each subject were also measured. The visual acuity, refractive error, amplitude of accommodation, positive and negatif relative accommodation, accommodation facility, accommodation lag, near point of convergence and heterophoria were tested for all subjects. Our results show that there was no significant effect of body posture on visual acuity, refractive error and binocular vision. Moderate head tilts, body tilts, head rotations and non-extreme habitual working distances of young adults do not seem to cause significant changes to their visual systems.

ABSTRAK

Tujuan kajian ini adalah untuk menentukan kesan postur badan ke atas akuiti visual, kesalahan refraksi dan penglihatan binokular. Postur badan semasa kerja dekat bagi 30 pelajar optometri yang tidak mempunyai pengetahuan tentang bentuk kajian ini telah diambil gambar dari pandangan depan, sisi dan atas. Sudut jongket kepala, condong badan dan pusingan kepala bagi postur badan kerja dekat untuk setiap subjek dianggarkan berdasarkan fotograf tersebut. Jarak kerja dekat biasa dan jarak kerja Harmon untuk setiap subjek juga diukur. Akuiti visual, kesalahan refraksi, akomodasi amplitud, akomodasi relatif positif dan negatif, akomodasi fasiliti, lamban akomodasi, titik dekat konvergens dan heteroforia diukur pada setiap subjek. Keputusan kajian menunjukkan postur badan tidak memberi kesan yang signifikan terhadap akuiti visual, kesalahan refraksi dan penglihatan binokular. Jongket kepala, condongan badan dan pusingan kepala yang sederhana dan jarak kerja yang tidak melampau di kalangan dewasa muda tidak menunjukkan perubahan yang signifikan daripada segi sistem penglihatan.

RUJUKAN/REFERENCES

Birnbaum, M.H. 1993. Optometric management of nearpoint vision disorders. Boston: Butterworth-Heinemann.

Ferris, FL Kassoff, A., Bresnick, G.H. Bailey, I., 1982. New visual acuity charts for clinical research. Am. J. Ophthalmol. 94: 91-95.

Harmon, D.B., 1951. The coordinated classroom. Grand Rapids: American Seating Co.

Harmon, D.B., 1958. Notes on a dynamic theory of vision. Austin.

Kraskin, R.A., 1991. What is Behavioural Optometry? What is Behavioural Optom­etrist? What is the behavioural concept of vision? Behav. Optom. 3: 4-5.

Lovie-Kitchin, J.E., 1988. Validity and reliability of visual acuity measurements. Ophthalmic Physiol. Opt. 8: 363-370.

Markham, C.H., Diamond, S.G. A Simpson, N.E. 1977. Ocular accommodative changes in humans and induced by positional changes with respect to gravity. Electroencephalo. Clin. Neurophysiol. 42: 332-340.            .

Marumoto, T., Sotoyama, M., Villanuev.a, M.B., Janal, H., Yamada, H.Kanai, A. & Saito, S. 1997. Correlation analysis between visual acuity and sitting postural parameters of young students. Nippon Ganka Gakkai Zasshi-Acta Societatus Ophthalmologicae Japonicae. 101: 393-399

McKee, M.C., Young, D.A., Kohl, P. Reinke, A.R. & Yolton, R.L., 1987. Effect of head and eye positions on fixation disparities, phorias and ductions at near. Am. J. Optom. Physiol. Opt. 64: 909-915.        

Scheiman, M. Wick B. 1994. Clinical management of binocular vision. Philadelphia: J.B. Lipponcott Company.          

Skeffington, A.M., 1928-1974. Optometric Extension Program Continuing Education Courses. Santa Ana, CA: Optometric Extension Program Foundation.

Skeffington, A.M. 1964. Introduction to clinical optometry. Optometric Extension Program Continuing Education Courses. Santa Ana, CA: Optometnc Extension Program Foundation.