So now we know something of the history of spectacles.
What percentage of the population wears spectacles?
That's a very high figure. What is the reason?
Apart from the many children and young people who are long or short-sighted, the ability to see near objects in sharp focus starts to deteriorate from the age of 25 meaning that from the age of roughly 40 many need their first vision aid, i.e. reading glasses.
Because the percentage of short-sighted people is increasingly rapidly and the population is ageing the percentage of spectacle-wearers is rising quickly.
Will a short-sighted person become long-sighted when they are older?
Age-related long-sightedness sometimes compensates for short-sightedness, especially in minor cases of short-sightedness, meaning that there is no need to wear reading glasses.
How do you notice if you have age-related long-sightedness?
You can no longer see small letters, or only with difficulty and with bright lighting. You may get headaches and the "arms grow shorter".
Are there any disorders which suddenly affect close-up vision?
Yes - high blood pressure (hypertonia), sugar diabetes (diabetes mellitus) and also certain types of migraine.
What types of vision aid are available?
Basically the ones already known: spectacles, contact lenses or surgical treatment.
Which types of spectacles are normally prescribed?
Children's glasses, long-distance glasses, reading glasses, work glasses, combined or "multi-focal" glasses.