Most people have more than one pair of shoes, but just one pair of glasses.
The shoes that you wear for gardening would be different to the pair that you wear to formal functions. Shoes for running will be different to shoes for going to work.
While, for many people, one pair of glasses can be functionally adequate, more than one pair can bring great benefits.
For people needing different prescriptions for distance vision and near vision, it makes sense to have different glasses for different tasks. For concentrated reading, a pair of reading glasses will be best. For going to the cinema, playing a round of golf or watching a match, a pair of distance glasses will prove to be ideal. But for tasks where different distances are needed to be seen, then some form of multifocal lens (bifocals or varifocals) will be most appropriate. For example, shopping, most jobs, going to dinner and needing to read the menu as well as chat to others, alternating between TV and reading/knitting/crosswords ... the list goes on.
Photochromic lenses (that lighten or darken according to how much light there is) are a great general purpose lens, giving protection against harmful UV light as well as shielding against brightness. However, they will not darken inside a car as much as most people need when driving on a sunny day - a pair of prescription sunglasses will do a better job for that.
Cosmetically, expecting to find one colour or style of frame to suit all the different clothes and looks that you might have is unlikely. Yes, you might find something that is fairly good, but one that is perfect? Unlikely! Glasses for work might be different to glasses for going out. Especially is you have to wear a particular uniform at work. Special events like a wedding, communion or confirmation?
Do you do any hobbies like DIY or gardening? Having a second pair of glasses help to keep your 'good glasses' looking good!
