Monovision refers to the technique that works by correcting the refractive error in one eye and making the other eye somewhat nearsighted. In this procedure, the corrected eye can see distant objects clearly but will need eyeglasses for up close vision. The nearsighted eye, on the other hand, can see up close objects clearly and will need glasses for far away vision. Monovision is a technique that has been used with contact lenses for years with great success.
Intraocular lenses, also known as IOLs, are medical devices (artificial lens implants) inserted in the eye to replace the natural lens. Monovision IOL corrects the patient’s vision by using lens implants with different focusing distances.
Eligible candidates for IOL monovision:
- Don’t like or cannot wear bifocals
- Cannot wear or don’t want contact lenses
- Have an active lifestyle, love outdoor activities and sports
- Desire high quality vision at near, distance and intermediate (all ranges) without contact lenses or glasses
Some people are not eligible for IOL monovision such as those who:
- Cannot pass pre-operative monovision screening tests
- Need perfect, fine stereo vision for their job, such as pilots
- Have significant astigmatism and are not interested in having it corrected
- Have a history of:
- Parkinson’s disease
- Stroke with severe side vision loss
- Eye muscle surgery, double vision or prism in their glasses
- Severe Graves eye disease (an eye disease related to thyroid disorders)
- Have experienced severe eye problems in the past in one or both eyes. These include:
- Lazy eye
- Severe diabetic retinopathy
- Acute glaucoma with significant loss of peripheral field vision
- Severe macular degeneration with medication injections into the affected eyeball(s)
Any combination of IOLs can be used for monovision including:
- Monofocal IOLs – These are the most common IOLs and have only one focusing distance. The IOL can be set to offer clear near, intermediate or distance vision.
- Multifocal IOLs -This type of IOL offers clear near and distance vision. It has different focusing powers that enable a person to see objects at various distances. The IOLs are designed to allow the brain to choose the right focus.
- Accommodative IOLs – These lens implants are designed to provide accommodation. It is the ability to focus at different distances by changing shape or moving inside the eye much like the natural eye lens.
Monovision IOL is often used in cataract surgery to decrease a patient's dependency on glasses after surgery. It can also be used for refractive lens exchange. This is a vision correction surgery that may help correct age-related loss of vision and reduce the need for contacts or glasses.
How does it work
An IOL set to far distances is implanted in the dominant eye and another set to near distances is placed in the non-dominant eye. Although the two eyes have different focusing powers, they can work well together to provide clear, blended vision at all distances. Monovision works because the brain adjusts the visual system to achieve clear vision when focusing on near and distant objects.
Modified monovision refers to accommodating or multifocal IOLs being used for monovision. This is because, besides the prescribed monovision effect, these IOLs are designed to offer an expanded range of vision.
Before the procedure, the eye doctor:
- Conducts a comprehensive interview about the patient’s lifestyle, job and hobbies
- Performs a complete eye exam
- Takes eye measurements to determine eligibility for monovision
- Selects appropriate IOLs with different powers to correct the eyes for near vision and distance vision
After Care, Recovery, Results
One can perform daily activities that need stereovision like navigating curbs, stairs and steps
If one decides they no longer want monovision, they can reverse the effects by wearing glasses
A pair of glasses for backup may be necessary for activities such as extended reading of small print or for nighttime driving
Increased focus depth with good near, intermediate and far vision reduces or even eliminates the need for vision glasses for most day to day tasks
Patients may experience a little compromise in subtle depth perception in some specialized tasks like threading a needle, which may need reading glasses