Now, protective wear in contact sport is not that uncommon, but it’s not all that usual in rugby. There is always a reason for it and Ian McKinley’s story is no different.

He made his professional debut for Leinster back in 2009, but was forced to retire from the sport in 2011. Why? A teammate’s stray boot perforated his left eye in a club game the year before. He played some club rugby after that, but then had to have more operations.

He had developed a cataract which he had to have removed. And he had to have his retina re-attached. Casual. Amazingly, despite all of this, he returned to professional rugby in 2014 thanks to his snazzy goggles.

Slade signed his first professional contract with Exeter Chiefs at the age of 18, the same year in which he also developed type 1 diabetes.

Now aged 22, Slade has adapted to life with diabetes, but admitted there was a moment he thought his career may have come to a premature end.

Slade says: “All I could think was: ‘I want to be a rugby player’ and I was questioning: ‘Can I do that?’”

Fortunately for Slade, he was told his rugby career would not be jeopardised, providing he was able to control his diabetes.

Lomu was diagnosed with nephrotic syndrome, a serious kidney disorder in 1995, and the disease had a significant impact on his playing career and wider life. By 2003 he was on dialysis and in 2004 underwent a kidney transplant. He then attempted a comeback but did not play international rugby again, and retired from professional rugby in 2007. He died unexpectedly on 18 November 2015 after suffering a heart attack associated with his kidney condition.

The former Bath and Wallabies hooker has a genetic disease, cystic fibrosis, that limits life expectancy to 38 years. He is the only athlete with the condition in the world who is playing a professional contact sport. He has defied the odds every day of his 30 years.

Charles has been talking a lot about cystic fibrosis these past few weeks and the world has heard his story.

He is comfortable talking about the disease. He takes upwards of 20 pills each day, is mindful of hygiene – "a simple cold can turn into quite a complicated chest infection" – but believes exercise is the best thing to control the sticky mucus build-up in his lungs and airways, which is the hallmark of cystic fibrosis.

Like Slade, he also has Type 1 diabetes. Chris says, "A large part of having diabetes has been very good for my rugby. It has taught me a lot about understanding my body and how it works which is very useful for a professional sports person."

Former England captain Moody was diagnosed with an inflammatory bowel disease called ulcerative colitis in 2005, but kept his condition secret while continuing to play top-level rugby.

Now retired, he wants to raise awareness of the Crohn's and Colitis UK charity which helps around 260,000 people in the UK with this type of disease.