How to protect your eyes from the sun, heat, water and champagne corks over summer.

When Nicole Kidman stepped out in Paris last year wearing big, wraparound sunglasses, ophthalmologist Shanel Sharma felt excited.

"As an eye doctor, I'm looking at that going, 'Oh my God, that's awesome' because if that takes off fashion-wise, it will also protect [people's eyes]," Dr Sharma says.

She's constantly urging people to properly protect their eyes from the Sun's damaging ultraviolet (UV) radiation so they don't end up on her operating list.

But often, she says, we buy sunglasses that don't do the job — or worse, actually increase the amount of harmful radiation getting to our eyes (more on that later).

But the Sun isn't the only reason summer can be hard on our eyes.

Many of us swim at beaches and pools, or just blast our air-conditioners more, which can dehydrate our eyes and make them more sensitive to that harsh Australian sun.

Ophthalmologists also see a range of injuries associated with outdoor activities, gardening or just popping champagne at parties.

So here's how to enjoy the Australian summer without sacrificing your sight.

Protecting our eyes from the Sun:

Australia experiences some of the highest levels of UV radiation in the world, and prolonged exposure can damage almost all structures, from the cornea (the clear outermost surface of the eye) to the retina (the light sensitive area at the back of the eye).

Cataracts, where the normally transparent lens becomes cloudy, have been linked to UV exposure.

And they're becoming more common in younger people, according to ophthalmologist Nisha Sachdev.

"Now I tend to do cataract surgery on people in their 40s and 50s, but in the past, it would only be the elderly."

UV exposure is also a risk factor for macular degeneration, which causes progressive loss of central vision, Dr Sharma says.

"Two of the top three causes of blindness are macular degeneration and cataracts, which are both related, in part, to ultraviolet damage to the eyes."

Then there's cancer. UV radiation is linked to ocular melanomas, which can occur in the uvea — the middle layer of the eyeball between the sclera and the retina — in structures such as the iris.

Basal cell carcinomas and melanomas can also occur on the eyelids and removing these can be challenging.

"When cancers are removed I have to take off a margin of normal tissue around the tumour to make sure we've got it all, and there's not a lot of skin there," Dr Sharma says.

UV exposure is also the main cause of pterygium, or "surfer's eye". It is a fleshy growth on the thin clear membrane across the eye's surface, called the conjunctiva.

Around one in every 100 Australians develop a pterygium. Those who spend a lot of time on or around waterways are particularly vulnerable, as water, sea foam and sand reflect UV rays into the eyes.

Finally, photokeratistis, sometimes known as sunburn of the eye, is another painful condition that occurs when the cornea is damaged by UV radiation.

Like sunburn on skin, symptoms include pain and redness as well as blurriness and swelling.

"In summer months I see up to 10 kids a week with this and parents are always shocked that it's possible," Dr Sharma says.

Kids' eyes need better protection:

UV radiation penetrates children's eyes more easily as their pupils are relatively wide and their lenses clearer than an adult's. It does the most damage to the macula (the area at the centre of the retina) from 0 to 2 years.

By the time children are between the ages of 9 and 11, around 30% have already sustained UV damage to their eyes.

Between the ages of 12 and 15, one in three already have a pterygium or a pinguecula (a yellowish growth on the conjunctiva that often develops into a pterygium).

For this reason, eye protection must start early — we're talking newborns — as this is when the damage occurs.

Dr Sachdev says too often, parents think they are doing the right thing by just putting a hat on their kids.

"Sunglasses on children needs to be promoted a lot more than what it currently is."

Picking the right sunnies:

The first thing to know is that a hefty price tag doesn't always equate to better protection.

"You can go and spend $300 on a pair that may not protect you," Dr Sachdev says.

Make sure the pair you are buying meets Australian standards. This ensures they protect you from UV-A and UV-B radiation, which both contribute to cancer.

But for the best protection, look for sunglasses marked "UV400". 

This means they will block radiation with wavelengths up to 400 nanometres, meaning they block almost 100 per cent of UV light.

The darker the better when it comes to lenses, and there are categories to help you compare pairs:

Category 0: limited or no UV protection

Category 1: limited sun glare reduction and some UV protection

Category 2: medium level of glare reduction and good UV protection

Category 3: high level of glare reduction and good UV protection

Category 4: very dark lenses for intense sunshine (on mountains and glaciers) but cannot be worn while driving.

Ophthalmologists recommend category 3 for everyday use, and polarised lenses to reduce glare.

Importantly, you should also look for a wraparound style a la Nicole Kidman (but don't worry, that doesn't mean having her budget).

If you buy sunglasses that don't cover the outer corners of your eyes, the light will still hit them from the periphery.

When sunnies work against you:

Dr Sharma says evidence shows some sunglasses which meet Australian standards actually increase the amount of damaging light reaching your eyes.

Let's say you're wearing a pair of sunglasses, but they are ill-fitting, or they fall under lens category 0 or 1 (which are still covered by Australian standards).

Your body will turn off your natural protective reflex to squint and let more sunlight in.

Essentially, your eyes are tricked into being relaxed at a time when dangerous UV radiation is still hitting them.

That's why some ophthalmologists say "fake" sunglasses (those which offer poor protection) can be just as dangerous as not wearing any at all.

Sunscreen around the eyes

We must protect that sensitive skin on and around our eyelids, so some ophthalmologists recommend applying sunscreen in that area as much as practical.

Mineral formulas, made from zinc, for example, are the better choice than chemical sunscreens. They are less likely to irritate sensitive skin and won't sting your eyes as you sweat.

Stick sunscreens are a good option too as they won't melt and are easier to apply.

Many tinted moisturisers also have high sun protection factor or SPF ratings (look for 30 but 50 is better).

Before you jump in the pool:

Our eyes can dehydrate during summer too.

Tears usually lubricate them, but dry air, heat and air-conditioning can cause these to evaporate, leaving you with stinging, burning eyes that feel like there's something in them.

Swimming in pools, rivers or the sea can exacerbate the problem, so make sure you wear goggles to keep the chlorine or saltwater out.

Even if you're not putting your head underwater, Dr Sharma says it's still better to wear UV goggles rather than sunglasses.

That's because goggles are flush up against the face and the UV radiation which reflects off the water can still find its way around sunglasses.

If you suffer from dry eyes, try some over-the-counter eye drops called artificial tears, and see a doctor or optometrist if your symptoms persist.

And for the contact-lens-wearers, the official advice is not to wear them while swimming (or even showering) as they act as a sort of cling-wrap over the eyes which pathogens can get stuck behind.

But if you must wear them, Dr Sachdev recommends daily disposable lenses. These can minimise the risk of any infections as you don't wear the same pair twice.

DIY and champagne injuries:

Many of us spend more time outside over summer playing sports, gardening or just doing those overdue home improvements.

Ophthalmologists see all kinds of "penetrating" eye injuries relating to these activities. Some need multiple surgeries, and in the worst cases, vision is lost.

Their advice? Don a protective eye shield if you're cruising through the bush on a mountain bike or just attaching the Christmas lights to the roof.

Dr Sharma says don't think "Oh it's only for two seconds", because it's in those two seconds that damage can be done.

Also, check your surroundings before popping a bottle of bubbly when you gather with friends and family for celebrations this festive season.

If the cork hits someone in the eye, even if the eyelid is already closed, the velocity at which it travels can leave the person with an eyeful of blood, or in some cases, a detached retina, Dr Sachdev says.

"I have been on call so many years on New Year's Eve when people have come in [to hospital] after a cork hits their eye, and they have zero vision.

"I'm very paranoid at parties. I tell people if you're going to ricochet the cork do so out in the open when no-one's around, or hold the cork as you twist it."

Original Story By | Paige Cockburn