Can an intraocular lens help with age-related vision changes?
PureSee IOL San Diego
A cataract is a clouding of the lens of the eye. This is a clear structure located just behind the pupil, and its function is to focus light on the retina, which is the light-sensing tissue at the back of the eye. The lens can change shape, which allows the eye to focus well at different distances.
When the lens develops a cataract, this blocks light from entering the eye and impedes vision. There’s no way to reverse the clouding of the lens, but a simple procedure known as cataract surgery can be used to address the problem and restore vision. This involves removing the damaged natural lens and replacing it with an artificial one, which is known as an intraocular lens or IOL.
There are several different types of IOLs, each with different characteristics. One of the newest options is the Tecnis PureSee IOL. This IOL offers an extended depth of focus, which gives it the ability to address not only cataracts, but also another age-related vision change known as presbyopia.
What is presbyopia?
Presbyopia naturally occurs with age, and it causes difficulty with seeing things close up. This happens because the lens of the eye gradually becomes stiffer as part of the aging process. The lens needs to change shape in order to change the eye’s focal distance, and as the lens becomes stiffer, this shape change becomes more difficult. Eventually, the lens can no longer bend enough to focus well on nearby objects.
Presbyopia is a normal part of the aging process, but it can make everyday life more difficult. Many people rely on reading glasses to help them manage, but it can be inconvenient to ensure that you always have these when you need them. Unfortunately, there’s no way to reverse the stiffening of the eye’s natural lens in order to treat presbyopia. However, when the lens of the eye is replaced during cataract surgery, there’s the potential for the IOL to address this issue.
Do IOLs treat presbyopia?
There are many different options for IOLs. Traditional IOLs are monofocal, meaning that they have a single specific focal distance. This is generally set for clear distance vision. Because this type of IOL can’t change shape, the patient will permanently be dependent on reading glasses for near vision.
PureSee is an extended-depth-of-focus (EDOF) IOL. Instead of a single specific focal point, it provides clear vision across a range of focal distances. This can greatly reduce a patient’s dependence on reading glasses. People with presbyopia have generally been relying on reading glasses for years, and PureSee can offer some freedom from the need for these.
What’s the difference between extended depth of focus and multifocal IOLs?
A multifocal IOL has multiple specific focal points. Some have just two focal points (one for distance vision and one for near vision, such as reading), while others also have a third focal point (for intermediate vision, such as seeing a computer screen). While vision is clear at each of these points, it will be blurry in the ranges in between the focal points.
By contrast, with an EDOF IOL, vision is clear across an entire range of focal points. With PureSee, the range is generally excellent for distance and intermediate vision, and extends into near vision as well.
In general, PureSee provides better contrast sensitivity than a multifocal IOL. This is because a multifocal IOL splits light across multiple different focal distances, which in turn can make it difficult to see in lower-light conditions (such as reading a menu in a restaurant or reading street signs in the evening). By using a range of focus instead of specific focal points, an EDOF IOL like PureSee is able to preserve contrast sensitivity. In fact, studies have shown that PureSee provides the same contrast sensitivity as a traditional monofocal IOL, while multifocal IOLs lead to reduced contrast sensitivity.
The tradeoff is that vision in the near range may not be quite as sharp with PureSee, because there is a limit on how large an IOL’s range of focus can be. PureSee offers excellent distance and intermediate vision, and near vision is generally good enough for most tasks. However, things like reading small print or doing very detailed close-up work may still require glasses.
PureSee also avoids the visual disturbances that can occur with multifocal IOLs. People with multifocal lenses often experience visual artifacts, such as halos or glare around lights at night. As the brain adapts, these artifacts are often reduced, but may still be present. With PureSee, the likelihood of these types of visual artifacts is far lower.
Should you choose a PureSee IOL San Diego?
When you’re choosing an IOL, you have a wide variety of options. PureSee is a great option for many patients, because it can greatly reduce the need for reading glasses while preserving contrast sensitivity and avoiding visual artifacts like halos and glare. However, the tradeoff is that they may not provide very detailed near vision.
It’s important to talk about your IOL options with an expert in the field, because each option comes with its own set of pros and cons. If you’re considering cataract surgery, please contact our front desk to schedule an appointment with one of our highly experienced eye surgeons. They’ll be happy to take the time to discuss your options with you, answer all of your questions, and make a recommendation based on your lifestyle and your goals for your vision.
