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Dry eyes, eye strain, blurry vision: 8 common eye symptoms and what they mean

What's normal and what's not?

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Eyes can act funky sometimes, but it's often harmless.

Getty Images

It's happened to most of us: You're laying down, scrolling through Facebook on your phone. You stand up and, all of a sudden, you're seeing stars and battling blurry vision. It subsides, though, and you shake it off. 

What's happening when flashes of light impede our vision or specks of light float around in our peripheral view? What about all those colors and patterns you see dancing across the backs of your eyelids when you close your eyes against bright light? 

These, and other symptoms, are common and usually harmless. This guide to eight ear oddities should help you understand what's going on when your eyes burn, itch, water, blur up or otherwise go wacky. 

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1. Symptom: You can make your vision blurry on command

What it is: Eye accommodation

If you can voluntarily blur your vision, near or far, fully or partially, you may have wondered if this is normal and whether you should ask an optometrist about it. It turns out that this ability is totally normal, although some people can do it more extensively than others and some people cannot do it at all. 

Eye accommodation is essentially the ability to "flex" your ocular muscles, thereby contracting and dilating your eye lens. This changes your point of focus or eliminates a point of focus completely, resulting in blurry vision. While considered harmless and normal, you should avoid intentionally blurring your vision if it hurts your head or eyes, or results in a lasting blurred sensation. 

2. Symptom: Your eyes keep watering, even in the absence of allergies

What it is: Dry eye, eye strain or environmental irritation

You might wonder: How can my eyes water so much if I have dry eyes? It's actually your eyes overcompensating for the dryness and producing excess tears to keep your eyeballs and eyelids lubricated. 

Eye strain also causes your eyes to water, often because eye strain involves keeping your eyes open for long periods of time without noticing it. If you don't blink often enough, your eyes will become dry, and they will attempt to remedy the problem by producing more tears. 

Environmental factors, such as bright sunlight, gusty winds, dust and cold air can irritate your eyes and cause them to water -- cold, windy weather in particular because both of those conditions dry out your eyes. 

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Your eyes are always producing tears, even when you're not crying. Dry eye can cause your tear ducts to overcompensate, and irritants trigger tears as a defense mechanism.

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3. Symptom: Your eyes feel dry and scratchy

What it is: Probably dry eye, possibly allergies 

The main symptom of dry eye is, unsurprisingly, dry eyes. It occurs when your tear ducts don't produce enough tears or your tears don't contain enough lubricant to adequately coat your eyes. Another primary symptom of dry eye is a scratchy feeling, especially when you blink or close your eyes. 

Allergies usually trigger watery eyes as a way to get rid of irritants, but dry eyes are also a symptom of allergies. Some allergens in particular, such as pollen, have been associated with dry eye symptoms, and these two conditions often coexist. 

4. Symptom: Your eyes burn and it's hard to focus on your screen

What it is: Eye strain, blue light exposure 

Eye strain is only a symptom, not a condition or disease. People use the term "eye strain" to refer to a collection of symptoms that arise when your eyes get tired from excessive use. Eye strain often occurs when driving for long periods of time, reading books or magazines, watching TV, playing games on a device or working at a computer -- basically, any eye discomfort you get from looking at something for a long time. 

Eye strain is considered normal and harmless and, contrary to popular belief, is not known to directly contribute to eye damage. Your eyes and vision should return to normal after you rest them. 

Blue light exposure is particularly notorious for inducing eye strain and may cause sleep disruption, but again, is not known to directly damage your eyes. If you're worried about eye strain and blue light, consider getting some blue-light-blocking glasses to wear while working at your computer or on your phone. 

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Blue-light-blocking glasses can help with the symptoms of eye strain.

Angela Lang/CNET

5. Symptom: You see specks floating in your vision

What it is: Eye floaters

Specks, spots, strings and spidery webs in your vision are called eye floaters. This visual occurrence is usually caused by age-related changes to your eyes, particularly the fact that the jelly-like substance in your eye called "the vitreous body" begins to turn more liquid-y as you get older.

Eye floaters may seem to drift around in your vision but speed away when you try to focus your eyes on them, or they may move around with your eyes. Age-related eye floaters can be annoying, but aren't usually considered a medical issue. 

See a doctor as soon as you can, however, if you notice a spontaneous increase in eye floaters, if you develop other eye symptoms, or start to feel an unexplained pain in your eyes. 

6. Symptom: You see colors, swirls and patterns when you close your eyes

What it is: Eye phosphenes

"Seeing stars" is a common phrase, and it stems from a real phenomenon. Eye phosphenes are a visual spectacle that encompass the colors, swirls, stars and patterns you see when you close your eyes. This occurs when you see light, but no light has actually entered your retina. 

Eye phosphenes often occur from pressure (such as rubbing your eyes); when you close your eyes against bright sunlight; if you sneeze or cough violently; if you go upside down and then revert (such as with a handstand); and when you squeeze your eyelids very tightly. 

Medical reasons for phosphenes include a sudden drop in blood pressure and migraines. Eye phosphenes are considered harmless, but if you see stars and flashes of light often or if they are accompanied by medical conditions or pain, you should speak with a doctor. 

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Eye phosphenes can look like any combination of swirls, patterns, stars, lines and colors.

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7. Symptom: You have a headache and tired, heavy eyes 

What it is: Eye strain, fatigue 

When a headache and tired eyes occur simultaneously, the culprit is usually eye strain, fatigue or both. As mentioned before, eye strain symptoms will resolve on their own once you give your eyes a chance to rest. Usually, headaches resolve on their own, too. 

If you're feeling very fatigued and it's hard to focus on the task at hand because of these symptoms, take a step away from whatever you're doing and do something to help resolve the symptoms. Try taking a nap, hopping in a quick shower or stretching for a few moments away from any screens or distractions. Getting outside may also help. 

8. Symptom: Your eyes burn when you close them

What it is: Something in your eye, eye strain, eyelid inflammation, dry eyes, allergies 

There are tons of reasons why your eyes might burn, from mild environmental irritants like dust to excessive screen time. Burning eyes can also signify allergies, eye strain, dry eyes, fatigue and a foreign object, such as an eyelash, in your eye. 

This is usually harmless and just your body's way of dealing with irritation -- most of the time, burning eyes will resolve on their own or after the root cause is dealt with (such as taking an allergy pill to reduce allergy symptoms). If burning persists after dealing with the root cause, increases in intensity or other symptoms appear, it's never a bad idea to get an eye doctor's opinion. 

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.