If you’ve ever pulled out your phone to show an older family member a funny post on social media, you might find that they make a similar expression every time: they’ll hold the phone away from their body, squint their eyes, and hold their mouth slightly ajar as they struggle to focus on the image on the screen.

Holistic Health HQ, “Presbyopia”, https://holistichealthhq.com/eye-conditions/, accessed May 2021.

It’s almost instinctual, and it’s an almost universal experience. But why could this be, and what are the physiological mechanisms behind this? 

You might have heard of farsightedness (also known as hyperopia), which is a condition where it’s easy to see things that are far away from you, but nearby objects appear blurry. Hyperopia commonly begins in childhood due to abnormalities in the shape of the eye or lens. However, farsightedness can also develop later on in life, and is especially common in older individuals aged 40 and up. This is known as presbyopia, which is a form of gradual farsightedness that is caused specifically by aging.  

What is Presbyopia, Exactly? 

Presbyopia, like hyperopia, is a refractive disorder characterized by a difficulty focusing on nearby objects. Both occur if light does not properly focus onto your retina; however, presbyopia is specifically related to the physiological changes that occur to your eyes as they age. 

The retina is the light-sensitive layer of tissue at the back of your eye that helps to relay visual stimuli to the optic nerve and produce the images our brains can interpret. The lens is one of the main refractive surfaces in the eye that helps bend incoming light rays to converge directly onto the retina. If light focuses behind the retina, as in the case of farsightedness, images that are nearby may appear blurry.

Dr. Mark Sorrentino, “Presbyopia (Aging Eyes)”, https://visionsource-drmarksorrentino.com/common-eye-problems/vision-problems/presbyopia/, accessed May 2021.

The most widely accepted explanation for why presbyopia occurs is due to the physiological changes that occur to the lens as we age. As kids, our eyes are born with an incredible ability to change the shape of our lens in order to focus light onto our retina. However, as we age, the lens becomes less flexible. Typically, when we try to see things up-close, our eyes use specific muscles that contract in order to bend the lens to a shape that allows nearby light rays to properly converge onto the retina. However, as we grow older, the ability to accommodate objects that are at close distances decreases due to a stiffening, or hardening, of the lens. This results in a much more difficult time trying to focus on objects that are close to your face. 

The onset of presbyopia begins in your mid-40s. Generally, symptoms of presbyopia present mildly at first, but worsen over time as your lens gradually loses flexibility. If you have presbyopia, you might find that after a certain amount of time, you may develop eye strains or headaches as a result of reading things close to your face. Or, as in the case we described before, you might notice that you need to bring objects further away from your face and squint in order to focus on them properly. 

How can I prevent it? 

Unfortunately, just as aging is an inevitable and normal process, there is no proven way to prevent the onset of presbyopia. However, the good news is that presbyopia is relatively easy to correct— there are many techniques that your optometrist can recommend to help with presbyopia, such as prescribing glasses or contact lenses, or even recommending eye surgery.

Regardless, there are still numerous ways in which you can practice good eye care techniques early on to protect your eyes from excess strain and reduce your chances of developing other age-related eye disorders, such as cataracts, glaucoma, and age-related macular degeneration. One way that you can protect your eyes early-on is to avoid excessive exposure to ultraviolet radiation by wearing sunglasses, UV-blocking spectacles, or contact lenses. It is also important to maintain a healthy diet, especially foods rich in Lutein, which can help protect against age-related macular degeneration. 

As a whole, it is important to understand that your eyes are constantly changing in response to your physical environment. While presbyopia is a natural part of getting older, practicing good eye care early on can still benefit you in the long run and overall improve your quality of life for years to come.