DO I REALLY NEED?

This week: Eyejusters, from £69, eyejusters.com THESE reading glasses have dials on each side, which allow the user to alter the strength of each lens.

EXPERT VERDICT: ‘Adjustable reading glasses may be useful as a temporary measure if you lose or break your reading glasses, or after a cataract operation, where there is a notable change in a person’s eyesight affecting one eye,’ says Daniel Hardiman-McCartney, clinical adviser at the College of Optometrists.

But off-the-shelf adjustable glasses do not perform as well as ready-made reading glasses, he warns. ‘While the adjustable lenses can provide a reasonable level of visual correction, due to the design it is unpredictable who they will be suitable for. Patients may alter the strength incorrectly. ‘In most cases, a pair of prescription glasses that fully correct for your needs will be the best option.’ He adds: ‘A study by the College of Optometrists in 2012 found that nearly half of ready-made spectacles do not meet British guidelines. ‘We recommend you have at least one custommade pair for most reading, with ready-made specs or adjustable glasses as a spare.’