The experience of having perfectly clear distance vision with contact lenses, only to find near objects like a phone screen or menu blurry, is a common frustration. Standard contact lenses are designed to correct a single focal point, usually for distance viewing, which does not account for the eye’s diminishing natural ability to focus up close. When you put in a distance-only contact lens, you are correcting one problem without addressing a separate, age-related change that affects near sight. This near blur is a sign that your eyes are likely undergoing a normal physiological change that affects nearly everyone.
The Biological Reason: Understanding Presbyopia
The primary cause of this difficulty with near vision is a condition called presbyopia, a gradual age-related process that affects the internal structure of the eye. Focusing on objects at different distances, a function called accommodation, relies on the crystalline lens inside the eye being flexible. The lens changes shape—becoming thicker and more convex—to increase its optical power and bring near images into sharp focus on the retina.
Presbyopia develops because the crystalline lens naturally hardens and loses this necessary elasticity over time. Concurrently, the ciliary muscle, which surrounds the lens and contracts to change its shape, loses some of its effective movement. Since the lens can no longer easily change its shape to increase power, the eye struggles to accommodate for close-up tasks. This reduction in focusing ability typically becomes noticeable, requiring corrective lenses, around the age of 40 to 45.
Corrective Solutions Available in Contact Lenses
For those who wish to maintain the convenience of contact lenses while correcting for both near and far vision, eye care professionals offer several specialized solutions.
Multifocal and Bifocal Lenses
The most comprehensive option is the multifocal or bifocal contact lens, which incorporates multiple prescription powers into a single lens. These lenses work using simultaneous vision, meaning they present both the distance and near correction zones to the eye at the same time, allowing the brain to instinctively select the clear image. Multifocal lenses come in a few designs, including concentric rings or aspheric (blended) zones. Concentric designs feature alternating circles of near and distance power, similar to a bullseye, while aspheric designs offer a gradual transition between prescriptions from the center outward. While this type of lens offers a seamless visual experience, some wearers initially report a slight reduction in contrast sensitivity or minor glare due to the multiple focus points.
Monovision
An alternative method is monovision, which uses standard single-vision contact lenses to assign a specific task to each eye. One eye, typically the dominant one, is corrected for clear distance vision, and the other eye is corrected for clear near vision. The brain then learns to prioritize the image from the eye that provides the sharpest focus for the current viewing distance. Monovision requires an adaptation period of one to two weeks, and while many people adjust successfully, some may experience a slight decrease in depth perception or struggle with night driving.
Hybrid Approach
A third, hybrid approach involves wearing distance-only contact lenses and supplementing them with over-the-counter reading glasses for extended near work. This option is often simplest for those who only need occasional near correction.
When the Prescription is the Problem
Sometimes, difficulty with near vision is not solely due to presbyopia but stems from an issue with the contact lens itself. One common cause is a distance prescription that is slightly too strong, known as an overcorrection. If the lens power is stronger than necessary, it forces the eye’s internal focusing muscles to work harder, creating a focal point the eye cannot naturally “unfocus” enough to see clearly up close.
Fluctuating or persistent blur at any distance, including near, can also be a sign of a poor lens fit or an underlying eye health issue like dryness. If the contact lens does not match the precise curvature of the eye, it may shift excessively when you blink or fail to center correctly, leading to intermittent blur. Dry eye syndrome, characterized by a poor-quality tear film, causes the vision to fluctuate, often clearing temporarily after a blink. If near vision blur is accompanied by discomfort, redness, or constant fluctuation, a comprehensive eye examination is necessary to determine if the issue requires a multifocal lens solution or a simple adjustment to the contact lens power or fit.