However, now you notice you are having a hard time reading your phone, the newspaper, your computer, a book etc. Sound familiar? Don’t worry—this is due to a natural process called presbyopia which occurs in everyone as we age.
The eye is a very complex organ, one of the components within the eye is called the lens. It is a flexible, balloon-shaped structure located in the middle of the eye that can change shape to focus the light entering the eye depending on whether you are viewing an object up close or far away.
Unlike other organs in the body, the cells in the lens do not die and regenerate. Instead, they continuously grow, making the lens thicker and thicker as the years past (think about an onion, the lens has a center and continuously adds “layers” over time getting thicker and thicker).
As this process occurs and layers are added over decades of life, the lens becomes less and less flexible, making it more difficult for the lens to change shape and therefore it can no longer alter focus from distance to near objects.
This process—of the lens hardening and becoming less flexible—is called Presbyopia and will happen in all individuals over time. Some may experience presbyopia earlier on in life, while others may not notice its affects until their late 50s or even early 60s.
This leads to the importance of reading glasses—reading glasses are prescribed (or can be picked up at a local drug store or grocery store over-the-counter) to help the lens perform its job of focusing incoming light correctly in the back of the eye.
Reading glasses are high in plus power and are used to focus light at a set distance (up close for reading, intermediate for computer, etc.).
You will find in the earlier years (mid-40s-50s) the lens still has some flexibility, and therefore one pair of low-powered reading glasses will likely get the job done and allow you to read up close again.
But with increasing age and less flexibility, the lens becomes more absolute, leading to the need for multiple pairs of varying powered reading glasses, or even a progressive lens that can be discussed with you with your favorite optometrist.
It is always best to make an appointment with an optometrist to ensure you are getting the correct power for optimal clarity. A power too low or too high can result in blur, eye strain, and fatigue.
However, generally speaking this chart can be used to estimate add power by age.
There are several other factors that go into choosing the correct pair of reading glasses; while over-the-counter “cheaters” may be able to get you by, an optometrist examines many different aspects of your eyes and therefore can decide on the best suited plan to meet your individual needs.
As we age, there are many different changes that go on in the eye, and therefore reading glasses are not always the perfect solution to your needs.
Some such examples include dryness, astigmatism, eyelid changes, decompensation of natural eye posture, and many others! Sometimes small combinations of each change can create a big issue, and you may only be treating a small part of the problem with reading glasses.
Another benefit of seeing the optometrist and getting prescription made reading glasses is that they can be custom-made for you. Eye doctors have the ability to create glasses in quarter diopter powers (0.25) so they can custom tailor glasses to be +2.25, for example, whereas it would be much more difficult to find such a specific variety in a local drug store.
Getting custom-made (prescription) glasses is the only way to get bifocals or progressive (no-line bifocal) lenses, which allow you to see not only at distance but also up close in one pair of glasses. Prescription glasses can only be ordered with a prescription from your local optometrist.
Bifocals are set for two working distances—up close and far away. Optometrists and opticians (who specialize in fitting glasses) will ensure the line is properly located in your frame to allow for easy transition from viewing at distance and near through the add power of the lens.
Trifocals are an altered set of bifocals which allow for three viewing distances—up close, far away, and an intermediate distance (often set for a computer or workspace environment). Like a bifocal, there will be an obvious transition line in the lens to help you focus on a certain working distance.
The main difference between a bifocal and a trifocal lens is that the trifocal lens will have two distinct lines to demarcate the transition between distance and intermediate viewing, and intermediate and near viewing.
Progressive lenses are also known as “no-line bifocals” or “invisible bifocals”, however they are actually more similar to a trifocal lens as progressive lenses allow for viewing at variable distances—distance, intermediate, and near, with a gradual increase in lens power from top of lens to bottom of the lens.
Progressive lenses tend to be a little more expensive than their lined counterparts but offer cosmetic relief for those who do not want a visible line in their glasses. They also add a more gradual change in add power and a smoother transition from distance prescription to reading prescription.
Regardless of type—bifocal, trifocal, or progressive lens, there are many different options of lenses available and your optometrist would happily help you decide which option would be best to fit your needs.