Vision issues are often the main reason a person seeks the services of an optiometrist, but what does it really mean when we’re told that our vision is blurry because we have a refractive error?

We see the world around us because of the way our eyes bend (refract) light. Refractive errors are optical imperfections that prevent the eye from properly focusing light, causing blurred vision. The primary refractive errors are nearsightedness, farsightedness and astigmatism.

Refractive errors usually can be “corrected” with eyeglasses (spetacles) or contact lenses, or they can be permanently treated with vision correction surgery.

How light travels through the eye

To see, we must have light. While we don’t fully understand all the different properties of light, we do have an idea of how light travels. A light ray can be deflected, reflected, bent or absorbed, depending on the different substances it encounters.

When light travels through one medium to another such as water or a lens, its path is bent or refracted. Certain eye structures have refractive properties similar to water or lenses and can bend light rays into a precise point of focus essential for sharp vision.

Most refraction in the eye occurs when light rays travel through the curved, clear front surface of the eye. The eye’s natural lens also bends light rays. Even the eye’s tear film and internal fluids have refractive abilities.

More on the eye and ‘refractive errors’ next week.

Very important: Always make sure you discuss and make decisions about your eye care based upon a formal appointment with your optician or doctor.

For more information please call us or visit

KOBRIN & MARTIN OPTOMETRISTS, SANDTON

Tel: 011 884 8413  |  kobrinmartin@telkomsa.net