A REVIEW OF ELECTRICAL ACTIVITIES IN VISUAL PERCEPTION: THE TRAVAIL OF VISUAL ACUITY IN HUMAN AND ANIMALS

A REVIEW OF ELECTRICAL ACTIVITIES IN VISUAL PERCEPTION: THE TRAVAIL OF VISUAL ACUITY IN HUMAN AND ANIMALS

¹Pofwon, P. Patrick, ²Yilleng, C. Godiya., ²Nendi, P. Gomos and ²Dabhim, D. Dashi

Plateau State College of Agriculture, Garkawa, Plateau State Nigeria.

²College of Health Technology Zawan, Plateau State, Nigeria.

ABSTRACT

The paper investigated the role of electrical activities in visual perception in human and animals. This review highlighted the Absorption of zero and one photon in visual perception, Measurement of visual acuity, Optical constraints on visual perception, Photochemistry of Vision and  colour vision, however Human ability to see is strictly dependent on the electrical signals  generated within the body. Among the recommendations, physics, is an umbrella of medicine and as such be made compulsory in all spheres of the medical practice.    

INTRODUCTION

The retina contains light transduction elements called photoreceptors which are the rods and the cones. Their names depict their morphology Arden and Hogg (1992)

The discs in the photoreceptors contain light sensitive chemical and these discs store a large concentration of Ca⁺⁺, the light incident on the eye meet the photoreceptors from behind. The absorption of light energy by these discs causes a change in structure of the receptors but not a change in shape. The absorption of light by the Ca⁺⁺ block and the Na⁺ release into the nerves leads to an inhibitory action of the light when it falls on the retina. This is a process of hyperpotamation of the nerves due to the light-absorption. The transmitter released by the photoreceptor is suppressed by hyperpotances, the second order neurons. By this process the light signal is signaled to the second order retinal neurons and from there to the visual cortex, hence depolarization of the rods in the Clark Arden and Hogg (1992)

          In short in visual perception, light energy hv is converted to electrical energy by the process of hyperpolarization by the photoreceptors.

Absorption of zero and one photon in visual perception

          The detection is assumed to be a noise free event and the distribution of photon in the test pulse is given by the poison distribution:

P(n, ) = e^-n   n

                     n

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