Answers to Common Questions About How Glasses Work

The eye is considered one of the most evolved features of human anatomy. Though it is quite complex, the way it functions is also straightforward. Light from a source, like a lamp or a sun, will bounce off of objects and into the eye. Entering through the pupil, the light that flows in is regulated by the iris. To prevent too much light from entering and causing damage to the eye, the iris enlarges or shrinks the pupil as needed. This adjustment is easy to notice when shifting from bright to dim environments and vice versa.

After entering the eye, the light passes through the lens, which focuses the light as it hits the retina. The lens will change shape as needed to create as precise an image as possible while focusing the light. An easy way to see this in action is by looking at an object close to you and then turning your vision to an object far in the distance. Your eyes will attempt to adjust and accommodate to the new circumstances. This process is made possible by the suspensory ligaments, which work to change the shape of the lens.

Though the human eye has evolved throughout millions of years, technology has advanced at a much more rapid pace. Artificial light, computer screens, and even books can cause the eyes to strain and cause deterioration. People will often need prescription eyeglasses to correct these vision issues, which can vary depending on the person’s lifestyle, genetics, and other factors. Still, there are a handful of common issues that people tend to experience with their vision. Myopia and hyperopia, near-sightedness and far-sightedness respectively, are the most widespread conditions that people encounter over their lives.

Near-sightedness and far-sightedness can be easily corrected with eyewear that helps to improve specific conditions. Other common troubles include astigmatism, which is caused by a lens or cornea with an irregular shape. This problem will cause vision to blur and make points of light appear less precise and more scattered. This can cause severe issues in low-light conditions or when attempting to drive a car after dark. Both children and adults can experience issues like myopia, hyperopia, and astigmatism. It is important to visit with an eye specialist to learn the best available solutions.

The easiest way to treat most vision problems is with prescription glasses. In a situation where a person is diagnosed with myopia, for example, eyewear with the right lenses will make it easier for a person to see clearly when looking at objects in the distance. For conditions like astigmatism, lenses can be treated in such a way that helps to reduce the impact of the irregularity’s distortion. Wearing glasses can help to make these conditions more manageable and aid with stress headaches, eye strain, and other issues related to vision impairment.

When you go about selecting the right glasses to suit your needs, you’re going to have a few options available to you. Plastic lenses are the most common type, as the material is perfectly suited to accommodate a wide variety of prescriptions. Plastic is also a durable material that can be treated to reduce the odds of scratches and other wear and tear. Though plastic is lightweight, polycarbonate lenses are even lighter. Good for high prescriptions, this lens material is thin and excellent for anyone who lives an active lifestyle or engages in athletics.

A third option that some people consider for prescription sunglasses is trivex. A bit thicker than other options, this material is great for UV protection and can accommodate higher prescriptions than other materials. Considered durable, many users state that this material creates the clearest field of vision. No matter what material you select for your glasses, it is a good idea to weigh the pros and cons of each option to be sure you are selecting the most appropriate fit.

A majority of people who wear glasses don’t know their exact glasses prescriptions. After visiting a doctor and receiving a diagnosis, a patient is likely to use the prescription information to purchase the correct glasses without actually knowing what the numbers mean. Essentially, the two numbers presented in your prescription are referring to your left and right eyes. These are abbreviated in Latin on most prescriptions, with OD referring to oculus dexterous, the right eye, and OS meaning oculus sinister, the left eye. The number itself requires a bit more thought to understand.

The OS and OD can be either positive or negative. The farther away from zero the number is in either direction, the worse a person’s vision is. A positive number will dictate far-sightedness and a negative number refers to near-sightedness. Additionally, astigmatism is determined by looking at the axis of the eye, which will be listed after the OD and OS. A prescription will always follow the same format and will look something like “-1.00 +2.50 x 180” or “+3.50 +2.00 x 45.”