My experience with monoculars and other aids


I want to tell you about my experience with monoculars.
For those who are not familiar with them, monoculars are valuable optical instruments that allow to bring into focus both near and distant objects. Basically, it is like half of a telescope. They are available in various sizes, even pocket-size and thus they are easily transportable.
For example, I always carry a monocular with me and I use it when I have to look at a road sign, a sign or a detail of a shop window or at the display showing schedules in railway stations. Some other times, it is useful to me to observe from afar a landscape (or at least to have an idea of how the landscape appears to my eyes!) or to read a caption in a museum with the comments of an art work. Among other things, it is useful for recognizing people from a distance and so on.
A few years ago I purchased my first monocular without knowing much about it (I was not even aware of our Association): I desired to have an easy-to-use aid that would help me when I had difficulties in looking from the distance. Today my desire has been more than satisfied. My monocular (which is worn-out by now), by an unknown brand (maybe it is Japanese or something like that), is a cheap one. Maybe for this reason it is not really precise, but it gives me no particular concern, because I know that, even if I lose it, I would not have thrown away a big amount of money.
Recently, at the meeting that the Association organised in Bologna in January, I got to show it to other achromats that gathered there. At that time there was also an exchange of information among those who owned one.
The interest that some achromats showed towards the one I owned, incited me to learn more about these devices and to be able to give some more information to interested people.
First of all, I went back to the shopkeeper who sold it to me, but unfortunately he no longer had that kind of monocular. I walked all over the city, but I did not find any shop where they could give much information about such aids.
However I found out that technically there are two kinds of monoculars: prismatic and Galilean. The first one, thanks to the peculiarity of its lenses, allows the focus by turning the two cylinders of which it is composed; it is very precise but proportionally also very expensive. To achieve a good result, it is necessary to use both hands. Among those that I could try or those I looked at in the catalogues, the best models cost around 250/300 €. Also for the second model, the focus is reached thanks to the rotation of a cylinder on the other, but it is more easy as, rotating on itself, the monocular gets longer, like a telescope. I personally find it extremely practical, because I can bring the objects into focus even with one hand. The cost is much lower: from 50 to 60 €.
For the people who are interested in it, it is good to mention what characteristics you should take into consideration while making your choice: the magnification power and the distance of the focus.
The number of the enlargements measures the monocular magnification ability. I could notice the following measures which are on the market: 4X, 6X and 8X, where “X” stands for “times” or magnification.
The distance of the focus also distinguishes between the minimum distance and the maximum distance. The minimum distance is very important because it measures the magnification ability and thus the possibility to use the monocular for close objects. The minimum distance that I have found ranges from 20 to 40 or 60 centimetres. However, the bigger the minimum focus distance is, the smaller the magnification power is: for example, a monocular with a minimum distance of 20 cm can hardly achieve the 8x magnification. On the market you can also find an adapter which, combined with the monocular, turns it into a microscope, so that you can read very small letters at a very short distance. Generally speaking, the maximum focus distance is infinity. This allows, therefore, to watch from afar.
I did a little research on the Internet about this aid, as I was motivated by both my curiosity and the interest that other achromats had shown for it. Among the many sites that exist, I found one that does not have much in common with optics and low vision aids (let alone with achromatopsia!), but in my opinion it can meet our needs.
Far from wanting to make advertising, I would like to mention website. It is a website where a company sells products which are related to electronics, modelling, mineralogy, numismatics and philately which can be bought by mail order. It apparently produces items which are very far from our needs. In fact, browsing the catalogue, or leafing through the paper one (upon request they send it to you in few days), you can find many interesting things: magnifying glasses of various sizes and features and, of course, monoculars.
I was intrigued not only by the lack of attention showed by shopkeepers in my city, but also by the reasonable cost of the monocular buying it online (51,65 € plus shipping costs), so I ordered a 8X monocular with a minimum focusing distance of 40 centimetres. After a few days I received the package – cash on delivery – and I realised with amazement that I had purchased a monocular (my second one, my spare one) that meets my needs.
Basically, sometimes, you can also spend a little to get decent quality aids, but what matters most, you can find effective tools to answer our unusual needs.
Francesco Bassani