Accommodation (focusing the eyes to clear blurred near images) and vergence (turning the eyes inwards to look at near objects) usually occur together automatically. If accommodation and vergence are disordered, blurred vision, double vision, reading difficulties and eye strain occur. In children, serious consequences such as squint, long or short sight can permanently damage eyesight if not treated correctly. These are common causes of referral to hospital and community eyecare services, but treatments are frequently poorly targeted, especially in community services. Dr Anna Horwood will study 1) Premature infant development and extend studies into adolescents and typical ageing adults; 2) How much traditional treatment methods rely on true treatment, in comparison to practice / placebo effects; 3) How the visual system adapts to sudden or gradual changes in demand such as occur with new spectacles or presbyopia (the natural decline in accommodation that occurs with age). By understanding how commonly used, simple treatments act we will be able to target them better and so save time and resources. We will also collaborate with a commercial manufacturer of child vision screening equipment to develop simple and effective methods of measuring eye position at the same time as refraction (focus).