These binoculars are made in the Far East, and may carry a name such as Tasco.They might be 20 or 30 GBP in Camera Shops, but are often seen new at carboot sales or as Special Offers in magazines etc for 10 pounds or so.
There is a similar 10x25 version for about the same price, but it's larger than 'pocket size' without offering any great advantage.
The focusing mechanism is accessible, and works by moving the objective [front] lenses; the further forward, the closer the focus. The cross-piece that moves the lenses engages with a peg screwed into each lens carrier. For some reason there is always, as far as I know, a choice of 4 holes to put each peg in.
Typically the first hole, nearest the eyepiece, allows focus from 1.8 m to 'almost infinity'.
The second hole gives 2.7 m to 'beyond infinity'.
You could obviously make a new hole for the peg such that max focus distance is precisely infinity.
It's easy with a 2mm drill and a 2.5mm tap, so long as you do exactly the same to the other carrier.
Locating a new hole such that min focus is at one metre will only result in a focal range of a couple of
metres or so.
The idea at this point is to allow the peg more travel by lengthening its slot.
The slot can be extended forward till it's about 10.5mm long before the mechanism is compromised. At this point
the two 2mm guide rods that stabilize the moving cross-piece come out of their tunnels. With the slot that size
expect focusing to one metre.
From the 'before' and 'after' pics you'll see the brilliant job done by using the wrong tool, an electric
drill with 2 to 3mm bit used as a sort of rotating file. Smooth the edges with screwdriver or
similar. The important thing is to keep aluminium fragments away from the eyepiece... cut a cardboard disk to
fit and drop it down the tube, then add some newspaper .... keep tube upright while working
on it... clean out afterwards without removing all the grease too.
Refit lens carrier, screw peg into chosen hole and test focus in monocular mode.
If the lens hits the rubber lens protector at close focus, refit the rubber inside out, or discard it.
Now do all that again with the other half, comparing new slot lengths to get them equal.
It's quite possible to reassemble with the pegs in place, as they were when you took it apart. If you decide to fit the pegs after assembly, take care you use the same hole with each eyepiece.
I have a pair of these 8x21s with the slot increased to 12.7mm, giving min focus of 80cm. This is only possible after fitting longer 2mm guide rods and extending the holes they run in. Bicycle spoke is fine for the rods. Trouble is there's not much overlap between fields of view at 80cm... it's like using 2 monoculars.