Swimming is hugely beneficial for your cardiovascular system but if you're not wearing goggles, your eyes might be suffering, especially if you're a contact lens wearer and you open your eyes underwater.
'The microorganism acanthamoeba lives in water and can cause serious damage if it gets into your eye'.
'Wearing contact lenses makes us more vulnerable because the bacteria attaches to the lens and can cause the surface of your eye to become inflamed and eventually infected,' says O'Brien.
Contact lenses will also naturally absorb any water around them, which could change their shape dramatically. This will make them uncomfortable to wear, often causing your vision to become distorted and blurry.
If you really must wear your lenses in the pool stick to daily disposables along with waterproof swimming goggles, or better still invest in a pair of prescription goggles which will help you see clearly without water coming in direct contact with your eyes.
Mascara can harbor bacteria which can cause infections leading to redness, light sensitivity and irritation and, in rare cases, even blindness. Liquid liner and mascara have a shelf life of around three months once opened.
Unopened, well-formulated cosmetics can remain stable for a couple of years.
What's more, eye make-up applied inside the eyeline, such as eyeliner, can increase the risk of eye infection, according to research from the University of Waterloo published in the peer-reviewed journal.
The research by the scientist Dr Alison Ng found that contact lens wearers were more vulnerable to infection from eye make-up. Dr Ng recommends preventing bacterial transfer by sharpening eye pencils thoroughly before each use.
Similarly, false eyelashes could put your eyes at risk. According to experts, false eyelashes are a hygiene risk because they tend to trap dirt and bacteria, while poor quality, unhygienic lashes increase the risk, so it's important to find a reputable beautician.
'Most optometrists recommended taking an eye test every two years, unless you have eye issues or are over 70, in which case, a test every 12 months is best to catch any health problems early,' says O'Brien.
That's because these screens emit blue light which is absorbed by vital cells in the eye's retina triggering toxic chemicals, which can eventually kill the photoreceptors we need for vision. And the older you get the more vulnerable you are.
The study's lead researcher Dr Ajith Karunarathne, an assistant professor in the UT department of chemistry and biochemistry says we shouldn't be checking phones and tablets in the dark, because this can dilate the pupils making them more vulnerable to damage.
Dr Karunarathne explains wearing glasses with an anti-glare coating that filters blue light, or adding a blue light filter screen to your phone or computer.
5. That casual smoking habit
We hardly need to say it: smoking is BAD, but few of us realize it damages our eyes. 'Smoking increases risk of cataracts and age related macular degeneration (AMD), which is a common condition that affects the middle part of your vision. In fact, AMD is Britain's leading cause of sight loss.
'Although the UV count is typically higher on sunnier days, it is important to bear in mind that up to 80% of UV radiation can penetrate cloud, meaning that forgetting to wear sunglasses on an overcast day can still damage your eyes,' says O'Brien.
And unless your sunglasses are offering good UV coverage, the tint means they will dilate your pupils and allow more UV light in than normal, so it's potentially worse than going without sunglasses if your glasses aren't up to scratch.
Look for styles that fit close to your face and don't let light in at the side and if you're a contacts wearer opt for brands like Acuvue with UV filters included or remember to wear sunglasses with your contact lenses.
Warning: Your eyes are even more susceptible to burning than your skin. As it's harder to tell when your eyes are getting burnt than it is when your skin starts turning red, it's easy to end up doing lasting damage to your eyes without knowing.
Leaving a fan running all night can increase irritation and dry eyes for contact lens wearers. Why? Because fans blow allergens like dust or pollen towards your eyes as you sleep, so that when you insert your lenses in the morning these deposits cause irritation and discomfort.
Consider setting a timer on your fan, so it switches off shortly after you doze off and wear a sleep mask, so your eyes are protected.
8. Over-using eye drops
While it's tempting to reach for the eye drops rather than put up with looking like a pink-eyed bunny, you can have too much of a good thing, say experts, as plenty of eye drops can lead to a rebound effect.
Rebound redness results because the blood vessels in the eye dilate as the effects of the medication in the drops wears off, creating a vicious circle. What should we do instead? 'Try to pinpoint the cause and deal with it, ' says O'Brien.
If, for example, your eyes are dry due to cold winter weather and central heating, invest in a humidifier and try not to sit too close to a radiator.
Rehydrate by drinking lots of water and eat plenty of foods rich in A, C and E vitamins and omega-3 fats, like salmon. And when the wind starts whistling, don your sunglasses to protect your eyes from the biting cold.
How often you can use eye drops safely will depend on the type, says O' Brien.
'There are two types: eye drops with preservatives and preservative-free eye drops. Eye drops that contain preservatives have a longer shelf life. The preservatives are chemicals that prevent bacteria from growing. This allows you to use one bottle of eye drops for a length of time.
'However, the preservatives in OTC eye drops cause eye irritation to become worse. Eye specialists typically recommend that you use this type of eye drop no more than four times a day.' Preservative-free eye drops are best for those with sensitive eyes.