Fred Starr recollects...

Materials World magazine
,
27 Nov 2019

Fred discusses the pros and cons of modern cataract surgery and replacement eye lenses

About a year ago, I came to realise the man staring back at me from the bathroom mirror was quite a stranger. Up to that time, my eyesight had become so bad that when getting washed and shaved, all I could see of me was an out of focus image. Without glasses, of course. When putting on my specs, all became clear, but the only picture I had of myself was of me wearing glasses. The new Fred Starr was the result of having cataract surgery at St George’s Hospital, London, UK. Strangely, friends and acquaintances have had no trouble with my facial transformation, I just get asked, ‘Didn’t you used to wear glasses?’.

Cataract surgery was essential, given my deteriorating eyesight. Daytime vision was dimming, but tolerable. My real problem was driving at night, when oncoming headlights were surrounded by an intense rainbow coloured halo, blanketing out everything else.

It is a diffraction phenomenon caused by the precipitation of fine particles of protein within the lens. So, as with Duralumin, ageing induces the formation of precipitates, but here it occurs in eyes rather than in aluminium alloys.

Serendipitous splinters

Cataract surgery is now routine and is simply the replacement of the occluded lens that did the work of focusing the image with one of plastic. In my case, the lens is made of poly methyl methacrylate, being one of the few materials that does not inflame the eye. It was a property noted by the ophthalmologist, Harold Ridley, who during WWII noticed that splinters of Perspex from smashed windscreens that got into pilots’ eyes caused no adverse reaction. In 1949 he did the first cataract replacement.

You can see what is needed from the rather gory magnetic resonance image of my head, which was not done in connection with the cataract. It was taken to ascertain whether I still have a brain – make your own judgement – and shows me before the operation. The messed-up lens sits at the front of the eyeball.

Being me, I asked if I could have the lens as a keepsake after it was removed and was then told something I didn’t want to know. Ultrasound is used to break it up. The resulting liquid is swept out, leaving an empty pocket and the replacement lens is slipped in.

It is as easy as that.   

Optical evolution

I was nine when I got my first spectacles. I kept fainting in school assembly for no apparent reason, but an extremely astute school nurse got me to take an eyesight test, which showed I was dreadfully short sighted in both eyes. This was one reason for being awful at sport.

It is almost 50 years since I got my first set of free, wire wound, National Health spectacles. Twenty years later they were taken up as a fashion accessory by John Lennon after he got hitched to Yoko Uno, but were absolutely unsuitable for an active kid, the glass lenses dropping out and smashing. We had to find the money for frames made of Bakelite, which gave more protection but the lenses could still break.

Spectacle technology did not change very much until the 1970s, when a non-reflection coating became available. The real advance came in the 1980s when plastic lenses came in. Today, there is a battle between glass and plastic, the latter needing a scratch-resistant coating but being essentially unbreakable. In response, you can now buy glass lenses that are toughened. Refractive index, or the power to bend light, is another area for competition. A high value gives thinner, lighter spectacles. The range of possibilities, along with titanium frames, made my last visit to the optician as difficult as buying a new shirt.        

Needing something squeezable

I thought that after my operation I would have left all of this behind. But no. What had not been made plain, when the consultants queried, ‘Do you want your new lenses shaped for close work or long distance?’, was that I would get what I asked for. Now, I can see the moon properly, but cannot read a newspaper. Cataract lenses are hard plastic and cannot be deformed by the squeezing of the ciliary muscles to bring things into focus. I now have three pairs of cheap specs of different strengths, bought from local chemists and supermarkets – one for reading, another for the laptop, and yet another for mending things.   

What I need is a deformable lens, which is the current target of research in what is termed intraocular medicine. When success is attained, as it will be, it won’t just help people with cataracts but will eliminate the need for spectacles altogether. Roll on to the future when we can see one another, and ourselves, as nature intended.