Does Wearing Eyeglasses Impair Your Peripheral Vision?

First depiction of glasses in Tommaso da Modena's 1352 painting.

Source: Tommaso da Modena

Eyeglasses have been around since the 14th century. In the early days, they consisted of two small magnifying glasses clipped to the nose and were worn by scholars for reading.

Skipping ahead six centuries, modern glasses now come in countless varieties: lenses made of plastic, glass, or polycarbonate; options for anti-scratch and anti-reflective coating; and of course, myriad possibilities for colors and frames, large or small, pointy or curved, thick or thin. Those of us with myopia (nearsightedness), hyperopia (farsightedness), presbyopia (farsightedness due to aging), or astigmatism now have endless choices when it comes to choosing our eyewear.

Nevertheless, there is one aspect of glasses that has not changed much over the last 650 years: their ability (or rather, inability) to improve the user’s peripheral vision.

Glasses are typically designed to optimize the acuity of our central vision. By carving a glass or plastic lens to the precise concavity or convexity, an ophthalmologist can create a distortion-free viewing experience that is tailored specifically for our central vision. This makes sense since many of the daily tasks that require high visual acuity occur in the center of our visual field.

When we read, we move our eyes from one word to the next, keeping the area of focus in our central field. When we drive, we move our eyes and head from the road to our dash and back to the road, always bringing the objects of interest back to our central vision. This is because the central part of the retina (the fovea) is densely packed with photoreceptor cones that allow for high-precision vision.

Despite the great care taken to improve our central vision, most glasses do nothing to improve our peripheral vision. In fact, the opposite can be true. For at least two reasons, wearing regular-framed glasses could actually impair one's peripheral vision, with serious potential effects on safety.

The first reason is the fact that, unlike contact lenses, glasses do not provide the wearer with a full field of view. Most people's horizontal field of view (how far we can see from left to right) is around 135 degrees. However, glasses tend to shrink the effective field of view to somewhere between 90 and 115 degrees, depending on the width of the glasses and their proximity to the eyes. So even in the best-case scenario, eyeglass wearers experience a smaller effective field of view than our glasses-less counterparts.

The second reason has to do with crowding. As any daily eyeglass wearer knows, there is an especially blurry region of the visual field around the frames of the eyeglasses. Even with “frameless” or "rimless" glasses, there exists a sharp divide between the part of the visual image that falls within the lens compared to what falls outside the lens.

This is exacerbated in glasses that have thick or opaque rims. The presence of these hard edges actually distorts visual information on either side of the edge, further reducing the reliability of peripheral vision.

These peripheral impairments are not without consequence. For example, a longitudinal study of 3,203 individuals found that people with peripheral visual impairments were 50 percent more likely to experience falls than those with intact peripheral vision (Patino et al., 2010). The authors suggest that targeting peripheral impairments will reduce rates of falling. A 2005 study of soccer players found that wearing glasses that limited peripheral vision resulted in slower sprinting and turning times (Lemmink et al., 2005).

The good news is that the brain can quickly adapt to new viewing scenarios. For instance, we can learn to move our head more or less quickly depending on the fidelity of our visual periphery.

Research by Gabriel Gauthier and colleagues found that participants who wore periphery-impairing glasses learned over the course of a few days to make quicker head movements in response to peripheral visual stimuli (Gauthier et al., 1987). This suggests that if new glasses come out with expanded fields of view, our eye movements and head-turning behavior would quickly adapt to account for the improved peripheral information.

More research is needed to examine the day-to-day consequences of impaired peripheral vision in eyeglass wearers. Daily activities such as walking, driving, and navigating social situations can all be affected by reduced peripheral vision. Even if we compensate by moving our heads more quickly, we may still miss a pedestrian crossing the street or overlook a friend walking past us.

Hopefully, eyeglass manufacturers will start incorporating this knowledge to design the next generation of eyeglasses that enhance our central vision without impairing our periphery.