Introduction History and symptoms is critical to determining whether an individual is suitable for contact lens wear, to aid selection and to inform management. The aim is to comprehensively elicit relevant information in as concise a manner as possible, as…
Introduction Diabetes mellitus is one of the most common systemic diseases in the world and it occurs when the pancreas does not produce enough insulin or when the body cannot effectively use that insulin. Hyperglycaemia (elevation of blood glucose concentration)…
Introduction Myopia is a commonly seen condition and is the most important cause of distance vision impairment. Data from many East Asian countries show a consistent rise in the prevalence of myopia from approximately 20–30% in the 1940s to 70%…
Introduction Rather than using contact lenses to add a new refracting surface to the eye to correct ametropia, in orthokeratology (OK), specially designed rigid contact lenses are instead used to temporarily alter the shape and thereby refractive power of the…
Introduction After corneal surgery, contact lenses may be indicated to provide improved optical correction or therapeutic ocular surface protection. Optical indications include the correction of irregular or high regular astigmatism, secondary aniseikonia and the correction of refractive error to eliminate…
Introduction The concept of a protective eye bandage originated in the first-century ad when Celsus reportedly applied honey-soaked linen to the site of a pterygium removal to prevent symblepharon development ( ). The therapeutic use of contact lenses goes beyond…
Introduction The contact lens practitioner is a key member of a multidisciplinary team involving paediatric ophthalmologists, optometrists and orthoptists concerned with ocular health and visual development of the child. Fitting infants and children with contact lenses is a challenging yet…
Introduction This chapter examines contact lens fitting for higher magnitudes of myopia, astigmatism and hyperopia. Prescribing contact lenses for high astigmatism ( Chapter 16, Chapter 17, Chapter 25 ) and hyperopia ( Chapter 27 ) is also covered in detail…
Introduction Congenital or developmental abnormalities of corneal topography include primary corneal ectasias, such as keratoconus and keratoglobus, and cornea plana ( Fig. 25.1 ). These atypical corneal shapes provide significant challenges to clinicians who are attempting to restore vision for…
Introduction A significant proportion of the population participates in sports or leisure-time physical activities. For example, a world-wide metaanalysis found that among adults, walking was the most popular activity in the Americas (19% of the population), Eastern Mediterranean (15%), Southeast…