"Children's orthoptics"

My son is seen regularly, he has astigmatism so it's very important that he has the correct prescription. He had an appointment in June 2020 which was cancelled due to the pandemic, it's now November 2020 and I haven't heard from them at all, no letters or phone calls. Absolutely no communication. He broke his nhs pair of glasses (which I paid £60 to have the lenses thinned down as they were too heavy for his face) and specksavers told me that they arent allowed to fix his nhs pair as he had a spare pair despite the spare pair constantly slipping down his face as they are too heavy. I know screening clinics are running so I'm baffled why routine screening is being done but patients like my son are being forgotten about.