Anatomy & Refractive States of the Eye

Debra Bennett

Debra Bennett has no relevant financial relationships to disclose. The content and format of this course is presented without commercial bias and does not claim superiority of any commercial product or service.

Course Description

A competent optician requires a basic understanding of the anatomy of the human eye, how it works, and what conditions or vision abnormalities might occur which may require their services. With this knowledge they may interact more confidently with patients and the prescribing practitioner as well. This course begins with an overview of the eye as an optical system as we survey its transparent and non-transparent structures. We follow a ray of light as it passes through the cornea, the aqueous humor, the pupil, crystalline lens and the vitreous humor on its way to the retina. The course continues with a discussion of the refractive states of the eye which include emmetropia and the various ametropias such as myopia, hyperopia and regular astigmatism. The optical cross is a graphical device which can be useful in illustrating the powers of the front and back surfaces of a lens in order to arrive at its total power. With this information a professional optician can read a prescription and identify which ametropia it is designed to correct as well as identify the meridians of maximum and minimum lens thickness.

Course Objectives

• Recall the anatomy of the human eye, how it works, and what conditions or vision abnormalities might occur
• Describe the different refractive states of the eye
• Demonstrate the ability to read a prescription utilizing an optical cross
• Identify which ametropia is present utilizing an optical cross
• Identify the meridians of maximum and minimum lens thickness