Before delving into the specific effects of technology on vision, it is

Before delving into the specific effects of technology on vision, it is important to rule out other factors perceived to be the cause of eye strain. For instance, screen time may not be the main factor leading to ocular discomfort. Rather, the cause could be the continuous near-vision tasks involved with technology. It was determined that there are significant differences in symptoms between reading aloud from a screen versus from a hardcopy. Subjects experience more advanced symptoms while reading off a monitor compared to reading from a paper. The most common symptom reported was blurred vision. This blurred vision led to difficulty refocusing, causing eyestrain. (Chu 2011).  

Mark Rosenfield (2016) provided an explanation as to why dry eye and eyestrain symptoms are much more severe while viewing computer screens, discussing the factors of screen time that contribute to the symptoms described by Chu (2011): gaze angle, text size, glare, and blink rate. When viewing screens, people tend to have their eyes at a primary (forward) or depressed angle. At the primary angle, more of the eye is exposed causing tears to be evaporated at an increased rate. Furthermore, the text on screens is relatively small. This forces the subject to focus intensely on the screen, causing a change in their blink pattern. To see the text clearly, people will blink less often or incompletely. The decreased and incomplete blinking contribute to the increased evaporation of tears. These components are why subjects from Chu’s study experienced more eyestrain when they read from a screen versus from a hardcopy.  

Now that it has been determined that screen time is the leading cause of symptoms related to ocular health, it is important to compare the different types of technology and screens. While subjects viewed a range of screen sizes and modes, Lee (2021) observed brain waves in different regions of the brain. The results paralleled Rosenfield’s observations: a positive correlation between screen size, advanced visual modes, and eye strain. This is because the large screens and advanced visual modes are inconsistent with the body’s natural sensory receptors. 

Experts have introduced a modern condition associated with the effects of technology on ocular health: computer vision syndrome, or CVS. This condition involves dry eyes and eyestrain caused by prolonged computer use. Not only do screens cause computer vision syndrome, long-term use leads to more serious conditions including glaucoma, cataracts, and dry eye disease.