LASIK (laser-assisted in situ keratomileusis) is a minimally invasive surgery that uses lasers to correct refractive errors, including myopia, hyperopia, and astigmatism. Over 30 million patients have benefited from this miracle of modern medicine. One of the most common questions LASIK patients ask before their surgery is, “Will I ever need glasses again?” The short answer is YES. Almost everybody will need reading glasses at some point, usually beginning in a patient’s 40s. As we age, our ability to focus on up-close images decreases – an inevitable process called presbyopia. In this post, we’ll discuss the nature of presbyopia and how LASIK and other surgeries can help patients minimize dependence on reading glasses.
Did You Know…?
The unaided eyes cannot focus on images at two different distances simultaneously. When your brain detects an object of interest, your eyes focus on that object in a singular plane. Any images further or closer than that plane become progressively blurry. Try focusing on your finger and an object over twenty feet away at the same time. You can’t! However, your brain and eyes can quickly change focus to track moving objects through space – like a tennis ball – or alternate between objects of interest – like the dashboard and the open road. But changing focus from distance to near becomes increasingly difficult as we age.
What is Presbyopia?
Presbyopia is the age-related loss of accommodation, leading to a progressive decrease in the ability to focus on near images. Before patients need reading glasses, they can change their focus from distance to near through accommodation.
Accommodation occurs with the contraction of a muscle called the ciliary body, which leads to a bending of the natural lens inside the eye and resultant nearsightedness. This nearsightedness helps patients focus on near images like a book or computer screen. Relaxing one’s accommodation then returns one’s focus to distance.
As we age, the lens stiffens, causing a corresponding reduction in our ability to accommodate. The result? Near images look blurry. But all is not lost! Like nearly everything else in optics, the problem of presbyopia can be managed with contacts, glasses, or surgery.
Death, Taxes, and Presbyopia
Benjamin Franklin famously stated, “…in this world nothing can be said to be certain, except death and taxes.” Old Ben also recognized presbyopia’s inevitability. Although there is no philosopher’s stone to reverse presbyopia, Franklin did invent bifocals to help us maintain the ability to switch quickly between distance and near viewing without having to procure our monocle (or reading glasses) from the depths of our pockets or desk drawers. Ben Franklin also invented electricity, used two centuries later to power the first LASIK surgery. Thanks, Ben!
LASIK’s Role in Presbyopia Management
LASIK – and other laser vision procedures like SMILE and PRK – work by changing the shape of your cornea so that it focuses images clearly onto your retina. Our corneas work best when they are monofocal, meaning they focus light onto a single point.
Previous attempts at using LASIK or other surgeries to create multifocal corneas have yielded suboptimal results, often causing haloes, glare, and other visual obscurations.
LASIK’s best answer to presbyopia is monovision: achieving clear distance vision in the dominant eye and clear reading vision in the non-dominant eye. LASIK, SMILE, and PRK can all target a specific refractive outcome with high precision, whether excellent distance vision in both eyes, excellent reading vision in both eyes, or “one of each,” i.e., monovision.
Many patients love the freedom from contacts and glasses that monovision allows, but monovision is not for everybody. Monovision should be trialed in contact lenses before pursuing this as a surgical target. Your optometrist and your surgeon can counsel you on the pros and cons of this decision.
There is no Free Lunch
Once presbyopia begins, we must sacrifice something to achieve clear vision at distance and near. Ben Franklin’s bifocals are still a common answer, but many patients experience visual “jump” between the top distance segment and the bottom reading segment of the bifocal. Enter progressive lenses, which aim to provide a smooth transition from distance to near vision. However, many patients have trouble focusing or finding the “sweet spot” in progressives.
There are multifocal contact lenses, which can provide a workable range of clarity but lack pristine clarity at any one distance. Contact lenses can also be used for monovision, but many patients cannot tolerate contacts for hours on end, especially later in life when dry eye is more prevalent.
Presbyopic patients who can’t find satisfaction in contacts and glasses often turn to LASIK for answers. I have personally treated countless presbyopic patients with LASIK, SMILE, and PRK, and nearly every patient is more satisfied with their vision after surgery than before. Underpinning this success is the detailed counseling I provide my patients on the nature of presbyopia and the limitations of monovision. Any elective surgery patient must have appropriate expectations for surgery, or the patient and surgeon will never be happy. “Undersell and overdeliver” is an age-old adage that has never failed me.
Pros of Monovision
Decreased dependence on contacts and glasses: I counsel my monovision patients that they will be glasses-free for 90% of activities, which presents a significant quality of life improvement for most presbyopes. However, they may want supplemental glasses for about 10% of activities: distance glasses for night driving or watching a long movie, or reading glasses for tiny print or prolonged reading.
Cons of Monovision
- Decreased depth perception: depth perception is best when both eyes can focus on the same target. The greater the near vision in the non-dominant eye of a monovision patient, the worse their depth perception. Many patients can adjust to this challenge, but some will not. The contact lens monovision trial is integral in determining which camp each patient will fall into before deciding on surgery.
- Decreased distance vision: distance vision is best when both eyes are focused on a distance target. Patients commonly have 20/20 vision in each eye independently but have even better 20/15 vision with both eyes open. However, in monovision, both eyes are not focused at distance, and the bulk of distance visual acuity comes from the dominant eye. This slight sacrifice in distance vision is usually a justifiable compromise to gain glasses-free reading vision.
- Decreased reading vision: Presbyopic patients require progressively higher strength reading glasses as they age, perhaps starting with +1.00 readers in their late forties and reaching +2.50 or +3.00 readers in their sixties. LASIK, SMILE, and PRK can target nearsightedness that mimics a +1.00 or +3.00 reader or anything in between. However, the more nearsighted the reading eye is, the worse the distance vision and depth perception. So, for patients who compromise for a nearsighted target of, say, a +1.50 reader, their reading vision after surgery will be slightly worse than before surgery in +2.50 readers. As I stated above, there is no free lunch!
Alternatives to Monovision
Various forms of presbyopic LASIK exist today, with more options available outside of the USA due to the conservative nature of the FDA. The creation of a multifocal cornea has not proven widely beneficial, but there are LASIK treatments that provide extended depth of focus by using the power of spherical aberration. The pros and cons of such LASIK treatment patterns are beyond the scope of this post, but you can discuss them with your surgeon if you are interested.
While laser vision correction is currently not well suited for creating a multifocal eye, artificial lens implants are an excellent option for presbyopic patients desiring freedom from contacts and glasses without the sacrifices of monovision. In refractive lens exchange (RLE), patients undergo lens removal before their natural lens develops significant cataracts, and their surgeon inserts a multifocal or extended depth of focus lens into each eye. Such premium lenses are very popular today but come at a higher out-of-pocket cost and can increase your chances of haloes and glare after surgery. Read our previous blog to discover more about RLE and other LASIK alternatives.
Conclusion
Ben Franklin said it best: there are “no gains without pains.” We cannot gain in age without the inevitable development of presbyopia; and presbyopic patients cannot achieve perfect vision at all distances without some sacrifice, whether that be the hassles of readers, the diminishment of depth perception with monovision, or the potentiality of haloes and glare with other surgeries.
Despite these compromises, millions of presbyopic patients have undergone laser vision correction such as LASIK, SMILE, or PRK to decrease their dependence on contacts and glasses. Most of these patients are more satisfied with their vision than before surgery, but laser vision correction is not for everybody. If you’re interested in a personalized evaluation and detailed discussion of your options, call 484-580-2166 or use our self-schedule link to schedule a free consultation.
Thanks for reading!
Jonathan Corsini, MD