The signs of a black eye include bruising and swelling of the eyelid and soft tissue around the injured eye, sometimes accompanied by broken blood vessels along the white of the eye, called a subconjunctival hemorrhage.
The discoloration starts out deep purple or blue, then may turn green or yellow before disappearing, usually in about a week.
But sometimes eye fatigue is a sign of an underlying condition that may need medical treatment. If eyefatigue persists despite taking simple precautions, see your doctor. This is especially important if your eye fatigue is associated with headaches or with eye problems such as:
Any activity that requires intense use of the eyes -- such as extended amounts of driving or reading -- can cause eye fatigue. These include extended periods of:
Exposure to bright light or straining to see in dim light can also cause eye fatigue.
One of the most common causes of eye fatigue is staring for long periods at digital devices such as:
This type of eye fatigue or eye strain is sometimes known as computer vision syndrome. It affects about 50%-90% of computer workers. Some estimates say computer-related eye symptoms may be responsible for up to 10 million primary care eye examinations each year.
The problem is expected to grow as more people use smartphones and other hand-held digital devices. Research shows that people hold digital devices closer to their eyes than they hold books and newspapers. That forces their eyes to work harder than usual as they strain to focus on tiny font sizes.
Digital devices may also be linked to eye fatigue because of a tendency to blink less often when staring at a computer screen. People usually blink about 18 times a minute. This naturally refreshes the eyes. But studies suggest that people only blink about half as often while using a computer or other digital device. This can result in dry, tired, itching, and burning eyes.
Symptoms of Eye Fatigue
Eye fatigue is associated with uncomfortable and annoying symptoms, such as:
Sore or irritated eyes
Dry or watery eyes
Blurred or double vision
Increased sensitivity to light
Pain in the neck, shoulders, or back
These symptoms can decrease your productivity. They may be intensified by sleep deprivation. During sleep, the eyes are replenished with essential nutrients. Lack of sleep may result in persistent eye irritation.