 The type of refractive error and how common they are vary enormously from region to region. The region with the lowest proportion of children at school with uncorrective refractive error is in Africa, where it's probably less than 2% of children have a refractive error. This is very different to Asia. Countries such as China and Singapore up to 80% of children now have been shown to have myopia. So there's a big variation in the proportion of children who have uncorrective refractive error and therefore need services. The age at which refractive errors develop also varies. So children who are long-sighted tend to be younger and they grow out of it as they grow up. So primary school children may have hypermatropia, but by the time they're 9 or 10, that's all got better on its own and they no longer lead spectacles. On the other hand, short-sightedness myopia is very uncommon except in China and it tends to develop around the age of 9 or 10. So most programs for the detection and treatment of refractive error outside China focus on children aged 10 years and above. Having said that, there is a great need for services for refractive error to be integrated into Ministry of Education and Ministry of Health's school programs. These are now expanding considerably and are receiving much more support because it's been realised that children who are not healthy or who are hungry or who are deficient in vitamins or who've got worms don't learn well. So there's a big initiative to try and cover many different conditions in school aged children and refractive errors can be seen as being part of that service and this means working with Ministries of Education as well as Ministries of Health. Again, if a team is going into a school to deal with refractive errors then there are all sorts of other things they can and probably should be doing. The teachers are likely to have presbyopia which will make their job difficult and marking homework in a poorly lit home environment is going to make that task very difficult. They may have glaucoma, they may be diabetic and have diabetic retinopathy. So addressing the health needs of teachers is not only good to improve their ability to be able to do their job but it'll also raise their awareness of eye health needs generally. Children also have other eye conditions like styes and conjunctivitis which needs to be detected and treated and they may have younger siblings at home who have locally endemic diseases such as glaucoma and vitamin A deficiency and children can be used as agents of change to take health messages home so that their younger siblings can also receive some benefit from the program. So I think it's important to think more broadly than just narrowly focusing on refractive errors and this can be an entry point into schools and into Ministries of Education to highlight the needs for the eye health needs of children generally.