When you're in your 20s, touring with a rock band about to hit the international big time and start seeing things, the natural conclusion is you've probably overindulged.
Not once did Kirk Pengilly from INXS imagine those "foggy halos" he could see around street lights after their shows in the mid 1980s were a symptom he had the "old person's disease" of glaucoma.
"I thought maybe I had had one or two too many drinks or I had conjunctivitis or something ... I wasn't concerned," Pengilly says.
"The next morning I awoke with excruciating pain in my eyes - I couldn't open them or do anything.
"It felt like someone was twisting daggers in my eyes."
The tour wrapped up and Pengilly returned to Sydney and went straight to his optometrist who diagnosed acute angle glaucoma.
Eye drops instantly relieved the pressure and then followed pioneering laser eye surgery which burned a tiny hole in the front of each eye, fixing his glaucoma permanently.
"I had come within a millimetre of going blind," Pengilly says.
"The extreme pain I had was caused by the pressure building up in my eyes. That then can block the blood from flowing into the eye via the optic nerve - then, the eye literally dies."
Glaucoma affects 300,000 Australians, with 50 per cent unaware they have the disease because they haven't had a comprehensive eye exam.
There is no cure for the condition and vision loss is irreversible, making early detection and treatment key to saving sight, says Glaucoma Australia.
Ambassador Pengilly says getting eyesight checked regularly by a professional is important because people may not even perceive the slight degradation.
He did not notice anything until the halos appeared, he added.
"The brain is very clever at hiding peripheral vision loss which is why the disease can sneak up on you," explains Associate Professor Ashish Agar, Glaucoma Specialist and President of the Australian Society of Ophthalmologists.
"Having check ups are crucial to every Australian's eye health, especially those with a family history of glaucoma."
To mark this year's World Glaucoma Week (March 6-12), Glaucoma Australia has set a 7 Sights in 7 Days challenge, asking people to "snap and share" images in their local area to raise awareness and money for research.
The campaign is an important reminder that sight enables people to do things they may take for granted, such as going for a run, riding a bike, snapping a photo or simply seeing loved ones, Pengilly says.
"My music career with INXS was just taking off worldwide, so I would have missed seeing everything in this amazing world," he says.
"More importantly, my daughter April was born a year later and I would never have known what she looked like or been able to watch her grow up.
"All sight is precious - we take it for granted."