July 16, 2014 1:33 pm

Eyeball-eating amoeba? 5 things contact lens users need to know

WATCH: Crystal Goomansingh reports on the dangers of disposable contact lenses

It’s a cautionary tale that’ll probably have you sticking to your doctor’s advice to change your contact lenses regularly and remove them each night: reports say a Taiwanese student went blind from an eyeball-eating amoeba after she kept her contacts in for six months.

Lian Kao’s story went viral on social media this week, and now optometrists and ophthalmologists are warning consumers to vigilantly clean and care for their contacts.

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In Kao’s case, she wore her limited-wear, disposable contact lenses for six months straight. Amoeba caught under her lenses and made its way to her corneas, causing permanent damage. The bug is called Acanthamoeba – a single-cell organism that can be found in tap water, swimming pools and hot tubs.

READ MORE: Student whose corneas eaten by amoeba a cautionary tale for contact lens wearers

“There’s no doctor on this planet that would say it’s okay to wear contacts for six months straight,” according to Dr. Joe Chan, who runs a private practice and is member of the Ontario Association of Optometrists.

“A lot of people think the eye itself is very clean but the reality is there’s a lot of bacteria and other organisms on the eye. Our eyes are able to deal with it as long as their defensive systems are working but when contacts are overused or worn overnight, it compromises the ability for the eye to deal with these problems,” Chan told Global News.

READ MORE: Contact lens abuse – why we do it and the potential dangers

He walks readers through five things contact lens wearers need to be aware of:

Contacts can cause infection:

Acanthamoeba isn’t the only culprit that could damage your eyes. Cornea ulcers – when your cornea is infected – are more typical.

“There will be a little white spot and that is an accumulation of white blood cells surrounding an area of infection on the cornea…this area can scar and leave a permanent scar on the surface of the cornea for the rest of the person’s life,” he said.

You’ll know if something’s wrong: your eyes will be red, irritated or dry. You could have chronic redness, sensitivity to light and eye pain. You could even encounter changes to vision.

READ MORE: Prolonged contact lens use leads to corneal issues for Bedford man

Your eyes need oxygen. Give them a break:

When you’re wearing contacts, the amount of oxygen that gets to your cornea is limited. While some lenses are designed for overnight wear, some experts still recommend against wearing them to sleep.

“Leaving them on too long can leave the cornea starved,” Chan explained. In response, excess blood vessels can form in an attempt to supply oxygen and nutrients, and in the long run, they can obscure vision.

Stick to wearing your contacts for about 12 to 16 hours at most, and take them off at night to give your eyes a break. If you wear them throughout the week, give your eyes a rest day on the weekend, too.

“That break gives [eyes] time to regroup, heal, and strengthen the immune system in that area,” Chan said.

Contacts shouldn’t be worn often while swimming, in hot tubs or showering:

Bacteria, parasites and other organisms tend to lurk in hot tubs or swimming pools. Chan says he’s seen infections in patients after wearing their contacts after water-related activities.

“It’s not particularly common, but in this situation, what ends up happening is the contact lens – in addition to being on the eye – is like a big sponge, and it allows organisms to sit on the eye and flourish,” Chan warned.

“For another person not wearing contacts, there would be nothing for [the germs] to grab hold of,” Chan said.

He suggests that if you’re wearing contacts while in the water, to keep your eyes closed, pat dry your eyes and clean your lenses thoroughly to make sure any bacteria that catches is killed.

Don’t wear your disposable contacts longer than the recommended time:

Your cleansing regimen is critical, especially if you’re wearing lenses meant for month-long use. Hang on to your lenses for longer than you should and you increase your risk of exposing your eyes to dirt and protein depositions that build up. With wear and tear, your contacts could also hang on to chemicals and preservatives from your contact solution. These issues can lead to irritation.

“You increase your risk of problems exponentially,” Chan warned. And don’t think of rinsing your contacts in water either. Tap water could have chlorine and other micro-organisms.

“If you soak your contacts in tap water, it can actually cause the shape of the contact lens to change,” he said.

Your contacts aren’t supposed to hurt while on:

If you place the lens onto your eye, and you feel pain or discomfort, take them off right away. Sometimes, small cracks can be seen along the contact’s edge. In other cases, a tear can form in the middle of the lens – that’s less obvious. If it’s dirt or sediment, your contact can be rinsed, but if you leave your contacts on with this tear or dirt, you could be scratching your eye.

During allergy season, those with severe allergies might even consider taking a break from contacts. The pollen, dander and other allergens can stick to your lenses.

carmen.chai@globalnews.ca

© Shaw Media, 2014

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