Glare occurs when excessive brightness interferes with clear vision. This sensation arises when light levels are greater than what the eyes can comfortably handle, making it difficult to distinguish details and objects. It is a common phenomenon many individuals encounter daily.
What is Glare?
Glare can appear as halos, rings, or starbursts around bright light sources, especially at night. It may also cause difficulty seeing in bright conditions, often with discomfort or irritation. Eye sensitivity to glare varies, with older people more susceptible due to age-related changes.
Glare is categorized into two forms: discomfort glare and disability glare. Discomfort glare is an annoying or painful sensation from an overly bright light source that does not necessarily impair visual performance. In contrast, disability glare reduces the ability to see by decreasing visibility. This type of glare results from light scattering within the eye’s optical system, creating a “veiling luminance” that reduces contrast and makes it harder to discern objects.
Why Glare Happens
Glare can arise from a combination of eye-related factors and external environmental conditions. Understanding these causes helps to explain why some individuals are more affected than others.
Eye-related conditions contribute to increased glare sensitivity by altering how light passes through the eye. Astigmatism, a common refractive error where the cornea or lens has an irregular shape, causes light to bend improperly, leading to blurred vision and the appearance of halos or starbursts around lights. Cataracts, characterized by the clouding of the eye’s natural lens, scatter incoming light, making light sources seem more intense and causing glare.
Dry eyes can also induce glare, as an unstable or thin tear film on the eye’s surface can scatter light, particularly at night. Additionally, individuals who have undergone LASIK or other refractive surgeries may experience temporary or persistent glare and halos due to changes in the cornea’s shape or internal light scattering. Presbyopia, the age-related hardening of the eye’s natural lens, can also contribute to glare as the eye’s ability to focus diminishes.
Environmental factors also play a role in the experience of glare. Direct exposure to bright light sources, such as oncoming car headlights or unshielded streetlights, can cause glare by overwhelming the eye’s adaptive capabilities. Reflections off reflective surfaces, including wet roads, snow, water, or even dirty windshields and eyeglasses, can redirect intense light into the eye, creating glare. High-contrast environments, where there is a large difference in brightness between objects and their surroundings, can also exacerbate glare, making it difficult for the eyes to adjust effectively. Even fine dust, air pollution, or smudges on lenses can scatter light, intensifying glare.
When to Seek Professional Advice
While occasional glare is normal, certain symptoms warrant a professional eye examination. A sudden onset of glare, especially if severe or interferes with daily activities like driving, should prompt a visit to an eye care specialist. Similarly, if glare progressively worsens or is accompanied by other visual disturbances, seek medical attention.
Seek urgent care if glare is accompanied by symptoms such as eye pain, sudden vision loss, or double vision. Other concerning signs include flashes of light, a sudden increase in floaters, or a “curtain” obstructing part of your vision. These symptoms could indicate underlying eye conditions that require diagnosis and treatment. Regular comprehensive eye exams help detect potential issues early.
Managing Glare
Several strategies can reduce glare. Wearing anti-reflective coated glasses can minimize reflections on lens surfaces, enhancing clarity and reducing glare from various light sources, including digital screens and headlights. For outdoor activities, polarized sunglasses are effective as they block horizontal light waves that cause glare from reflective surfaces like water, snow, and roads.
Adjusting your environment can also make a difference. For instance, modifying screen brightness and contrast on electronic devices can reduce digital glare. Ensuring eyeglasses and vehicle windshields are clean prevents light scattering from smudges or dirt. Using visors or hats outdoors can block direct sunlight from entering the eyes. Inside, positioning light sources to avoid direct reflection or opting for indirect lighting can create a more comfortable visual environment.