The common experience of contact lens discomfort often leads to a throbbing head. Many people wonder if the blurry vision or gritty feeling from lenses worn past their prime can truly cause a headache. The answer is yes, and the connection is rooted in a complex chain of physiological and physical reactions within the eye.
How Lens Degradation Causes Discomfort
An “old” contact lens, whether past its expiration date or worn too long, undergoes physical changes that compromise comfort. The surface of the lens acts like a sponge for components in your tear film, including proteins and lipids. Over time, these elements accumulate and denature, creating a rough, sticky layer on the lens surface.
This accumulation turns the smooth lens into a source of friction, causing a gritty or scratchy sensation with every blink. The deposits also interfere with the lens’s ability to maintain hydration, leading to increased dryness and irritation of the corneal surface. A contaminated lens can harbor microorganisms, which increases the risk of eye inflammation and infection.
The Connection Between Eye Strain and Headaches
The physical irritation from a degraded lens triggers a chain of events that culminates in a headache. When a lens is worn longer than recommended, the accumulated deposits and reduced water content restrict the flow of oxygen to the cornea, a state known as ocular hypoxia. The cornea reacts to this deprivation by swelling, a condition called corneal edema.
Lens degradation leads to fluctuating or hazy vision due to the surface deposits. To clear the blurred image, the eye’s focusing muscles, the ciliary muscles, strain to compensate. This constant overworking of the ciliary muscles creates tension that radiates outward, resulting in a tension headache commonly felt across the forehead, temples, or behind the eyes.
Adhering to Replacement Schedules
A contact lens becomes “old” the moment it exceeds the prescribed replacement frequency, regardless of how clean it looks. This schedule—which may be daily, bi-weekly, or monthly—is based on the material’s structural integrity and resistance to deposit buildup. Adhering to this schedule is the primary defense against the degradation that causes discomfort and headaches.
Using a lens past its recommended lifespan reduces its oxygen permeability and compromises its surface. For reusable lenses, proper cleaning and disinfection techniques are essential to wash away accumulated proteins and lipids. Replacing the lens case every three months also prevents the transfer of contaminants, ensuring the new lens performs optimally.