Education on the anatomy of the eye and how it works is the first step to understanding why its’ protection is critical. Consider your eyes as cameras. They provide you with images of the world around you. The front structures of the eyes are the lenses of your cameras that focus light rays through to the back surface. The camera body is the eyeball and the processing chip or film is the rear inner surface that captures the light to be processed. The eye works similarly in that the tears, cornea, and lens focus the light through the vitreous gel in the middle cavity to the retina at the back of the eye. The optic nerve mimics a processing cable which delivers the data to the brain to create the final image display.
The cornea is the clear, round, dome-shaped outer membrane of your eye. It has no blood vessels and receives most of its oxygen from the air. A small scratch on the cornea can be very painful as it is made up of more fibres per unit area than any other place on the body.
The anterior chamber is the space behind the cornea and in front of the iris that contains a clear, nutrient fluid. The trabecular meshwork is a circle of specialized tissue where aqueous humour drains out of the eye. It is located at the intersection of the cornea, the sclera (the white part of the eye), and the iris.
The pupil is an opening in the paper thin iris. The iris is one part of a layer which wraps itself around the inside of the eye called the uvea. The iris contains a circular muscle that constricts the pupil in brighter light, and radial muscles that dilate the pupil in lower light. These abilities allow for clear vision in most lighting conditions. The pigmentation of the iris determines the colour of your eyes.
The lens is shaped like a round magnifier and is located behind the pupil and iris. In conjunction with the cornea the lens will focus light rays through the vitreous to the back of the eye.
Vitreous, also known as vitreous humour, is a sticky gel with several firm attachments to the retina, is virtually clear, and makes up the vitreous cavity of the eyeball.
The white area of the eye consists of several layers including a clear protective layer, the conjunctiva, a white layer, the sclera, a pigmented layer, the choroid, and finally a thin film of tissue that coats the inside of the eye, the retina. Each cell in the retina is connected to a nerve fibre and all the nerve fibres come together in a bundle called the optic nerve.
With this knowledge about eye anatomy and function, you can understand why protecting these “devices” is required for a lifetime of use. Your eyes can be exposed to dangers not only in the work environment but around the home, in the yard, while playing sports and during other physical activities. Awareness of potential dangers and an ongoing assessment of eye safety risks associated with your lifestyle along with the use of the proper protective eyewear are required.
If you wear corrective lenses, you may obtain prescription safety glasses through your local optometrist. These products are manufactured to follow specific industry safety standards and must include impact resistant industrial thickness lenses. A wide variety of frames and lens styles are available to ensure protection of your “cameras”.
By Darren Mirau, LO, LCLP, occupational vision care (OVC) coordinator, Saskatchewan Association of Optometrists (SAO)
For information about a comprehensive Prescription Safety Eyewear Program, personalized for you company, please contact Darren Mirau, OVC Coordinator at the Saskatchewan Association of Optometrists (SAO) at 306-652-2069.