Former MP ‘had no clue’ he had glaucoma before routine eye test

“I had absolutely no clue that there was anything wrong,” Mr Tyler said.

Described as the “silent thief of sight”, glaucoma affects about 700,000 people in the UK.

It is usually caused by fluid building up, external in the front part of the eye, leading to the optic nerve, which connects the eye to the brain, becoming damaged.

The condition does not usually cause any symptoms to begin with and can develop slowly over many years.

Mr Tyler, the former Liberal Democrats rural affairs spokesperson who became a life peer in 2005, said he remembers the day when he discovered he had glaucoma “precisely”.

“It was the day of the [Twin] towers 9/11 in New York – when I went for my usual sight check,” he said.

“I was an MP in rural Cornwall. I knew nothing about glaucoma. My eyes seemed to be fine.

“Like many people, I think you sort of take these things for granted. It is literally out of sight, isn’t it. So, I was completely taken aback.”