Walsh revealed that he suffers 'seriously bad' with a disorder called blepharitis that makes his eyes swell up and appear red, as well as other side effects.
The 61-year-old told This Morning viewers that his adoring fans usually aren't aware of his condition, for which he takes regular medication, and don't realise how much he struggles with it.
He said: "People don't realise I have seriously bad blepharitis.
"I have to take one pill a day for it or I really struggle. I am going to need my eyes operated on at some point to sort it out.
"So many times, people have commented on how I look. But they don't realise. If I take medication though, I'm fine."
He's actually spoken about his condition previously on ITV's morning show, telling hosts Eamonn Holmes and Ruth Langford about how his eyes become crusty around the eyelashes, and his face around the eyes swells up.
In certain bad cases, blepharitis sufferers can even wake up with their eyelids stuck closed.
It's not life-threatening, but it can lead to all sorts of other nasty problems such as conjunctivitis and cysts.
Not great, but washing your eyelids regularly and taking the medication will usually do the trick.
Walsh also explained how he recently lost 10lbs after receiving a stark warning about his weight from the doctors.
He said: "I was a time bomb. I was quite lucky in regards to the calcium test but my doctor said I produce too much cholesterol. It's a silent killer.
"My heart guy said, 'Look, Brad, you need to get fit',
"I thought, 'Oh crikey, I'm gonna be bang in trouble here if I don't lose the weight and start dealing with this'."
Following that advice, Brad dropped nearly a stone in weight in a bid to better his health, which will no doubt be of relief to the millions of fans of The Chase.
Brad went on to explain how he managed to lose the weight, explaining: "I started watching what I eat. I stopped drinking immediately because of all the hidden sugars, started eating more fruit, vegetables, salads, and fish.
"I've stopped eating cakes, breads, pasta, and we got a puppy, a Shiba Inu called Lulu - not after the singer - which has been brilliant because she's got me out walking every day now."
Featured Image Credit: ITV