Does anyone know if there's a big difference in lens thickness between a +2.75 to a +4? We're on 3 monthly appointments so I'm concerned about paying for thinning if we have a new prescription in 3 months, but I don't want the glasses to be really heavy. The current +2.75 aren't too bad, but they said they would build up to a +4.
Does anyone recommend any opticians for reasonably priced thinning on children's glasses? Specsavers thought it would be £100 per pair !