Have you ever heard the term, “wired and tired?”

Even if you’re not familiar with the phrase, odds are you’ve experienced it. The dry, weary eyes after staring at your desktop for too long. The brain melt that comes after watching too much television. The head and neck aches and even the nausea that comes after too much computer use.

Yes, most of us know the physical and mental fatigue all too well that comes from using our computers, TVs, tablets and phones for hours on end. According to a report by The Vision Council, more than 90% of American adults spend two or more hours per day in front of some sort of screen, nearly 60% spend five or more hours, and 30% said they look at screens more than nine hours per day.

It’s understandable — digital devices have become a critical part of our productivity and quality of life. But what is this really costing us?

Electronic screens aren’t just leaving us wired and tired, they’re affecting our health in a very real and very damaging way. Here’s how.

BLUE LIGHT

Most digital screens are backlit and emit blue light, or high-energy visible (HEV) light wavelengths. Research has shown that overexposure to this light can contribute to eyestrain and discomfort, and even lead to more serious conditions later on such as macular degeneration.

Blue light has also been shown to suppress melatonin — the sleep hormone — desynchronizing the body clock and causing an artificial feeling of wakefulness. And this can lead to a number of other complications, such as hormone imbalance, depression, and even brain inflammation.

THE CORTISOL HORMONE

The cortisol hormone helps the body manage stressful situations by increasing blood sugar levels and reducing the response of the immune system. But research has shown that prolonged use of electronic devices can overstimulate your cortisol production — which can have notable effects on the brain. Excess cortisol levels can not only weaken your ability to control stress, but can actually cause your brain to shrink, which compromises your ability to concentrate, make decisions, sound judgments and interact socially.

PROBLEMS FOR CHILDREN

Many children are hooked on television and electronics. In fact, most American children spend about 3 hours a day watching TV. And when you factor in computers, tablets and gaming devices, that number climbs to about 5 to 7 hours a day.

Because children are much more sensitive and malleable than many realize, it doesn’t take much electronic stimulation to take its toll on their still-developing minds and bodies. And the ever-increasing screen time has been shown to lead to sleep, mood, and cognitive issues including:

• Sensory overload
• Lack of restorative sleep
• Hyper-aroused nervous system
• Depressive states
• Reduced physical activity levels
• Fractured attention span
• Depleted mental reserves
• Desensitized brain reward system
• Stunted emotional development

INSULIN LEVELS

In a study of nearly 500 sixteen year olds, those who spent more than two hours a day using computers and other digital devices had higher insulin levels than those who spent less time in front of the screen.

Insulin plays a critical role in your metabolism and your blood sugar levels. When insulin becomes too high for too long, the cells of your body start to ignore it, and your body becomes less and less effective at absorbing glucose and producing energy. This means that most of what you eat will be converted into fat, and your body begins to accumulate more of that fat in your liver. Other signs and symptoms of chronically elevated insulin include abdominal obesity, elevated blood sugar, acne, hair loss and high blood pressure.