Ageing and its challenges for vision, mobility

Tola Adeniyi, a veteran journalist, gave a vivid illustration of the challenges in old age using the great jurist, Prince Bola Ajibola as an allegory. Movements generally tend to slow down with age. Of course, there are always exceptions to the rule.

Chief Olusegun Obasanjo, Prince Ajibola’s schoolmate in High School, former President of Nigeria is clearly an exception and all who have had the opportunity of walking with him would attest to this.

I had the opportunity of walking along with him on the long stretch of the corridor of the Obasanjo Library about two years ago. I am a much younger man, but couldn’t cope up with his pace! He was walking and I was running to catch up with him!

But old age it is not all about mobility, we also learnt last week that there are vision challenges with the coming of age. Ageing is the greatest known risk factor for most human diseases. About 150,000 people who die each day across the globe, die from age-related causes. We also learned that the effect of age on the eyes usually bares its fangs at about the age of 40.

We read about Mr Presbyope who had increasing difficulty reading small prints. In order to be able to read, he had to place the book at arms’ length. In addition, he found out that he needed stronger illumination.

Towards evening, on his very busy days, he always ended up with a bad headache and his eyes ached like never before. He cried for help when it became unbearable after suffering in silence for about four  years.

His problem was found to be age-related and solvable with the use of glasses. He was however, advised to have a thorough eye examination before obtaining a pair of glasses because there could be other co-existing problems of age, such as Glaucoma.

Mr. Presbyope envied his 58-year-old friend who could read without any glasses. “Why is he different when he is 12 years older? And then my 30-year-old friend (Mr. Hyperope) already has difficulty reading. Why?” I couldn’t answer these questions before I ran off to the Maundy Thursday event last week. So I’ll take off from there.

We all can guess accurately why Chief Obasanjo could walk briskly like a 40-year-old while neither his school-mate, Prince Ajibola (possibly in the same age bracket) nor myself, a much younger man, had to run after him! But explaining this is a little much complex and requires a knowledge of physics.

Rays of light from a distant object must be focused on the inner layer of the eye (retina) to be seen clearly. In longsighted persons, the rays fall behind and the eye has to use extra energy (accommodation) to bring them to focus on the retina. This energy has to be supplied from the bank reserve used for near work such as reading.

Ageing leads to a gradual loss of this energy reserve which usually manifest at about the age of 40. Mr Presbyope, you see perfectly well for distance, but your problem is reading because of loss of in accommodation owing to age. All you need is a pair of glasses of the appropriate power.

In your friend, 30-year-old Mr Hyperope, the rays fall so much further behind the retina that his energy reserve (even at his young age) cannot cope. So, the extra amount has to be supplied by a pair of convex glasses. Even though both of you seem to have difficulty reading, Mr. Hyperope’s problem is quite different from yours.

When he turns 40 or more, he will still require about the same additional correction you require now to be able to read. Because both of you have to struggle to see clearly without your pair of glasses, you experience eye pains and headaches.

“What about my 58-year-old friend, Mr Myope, who can read without glasses?” Mr Presbyope reminded me. Interesting! The rays of light from the distant object fall in front of the retina so it is blurred. So it is for near object. To see it clearly, he has to move closer.

Remember, you have to move it far from you! So Mr. Myope has an advantage. He can read clearly at near when he is not wearing his distance correction. Once he puts on his glasses for distance, he loses this advantage so he becomes exactly like you except his glasses have that extra energy commensurate with his age.

Old age vision challenges are not about glasses alone. With increasing age, the normal lens inside the eye gradually loses its clarity leading to a reduction in the amount of light entering the eye and visual loss. When the loss of vision starts limiting one’s day to day activities, the cloudy lens is called a cataract.

There is only one way to deal with a cataract – surgical removal and replacement with an artificial lens. As you approach the age of 70, (sometimes before but may much later) one may develop age-related macula degeneration.

Activities such as unaided movement, even within the house, reading, writing and watching TV may become impossible in advanced stages.

If, unfortunately, you have developed, along the way, glaucoma, diabetes, hypertension, stroke, arthritis or memory loss, we might as well complete Shakespeare’s seventh stage, “Last scene of all that ends this strange eventful history is second childishness and mere oblivion, sans teeth, sans eyes, sans taste, sans everything.”

Next week, we shall discuss how we can mitigate the effects of ageing on our lifestyle.