Optician using a keratometer to measure the radius of curvature of the patient's cornea. A reading is taken by superimposing two patterns projected onto the cornea. Accurate measurements of the curvature are needed when fitting contact lenses,and when investigating disorders such as astigmatism (ab- normal curvature: surface resembles an egg rather than a sphere) and glaucoma (excessive pressure of internal fluid) | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / McClenaghan, Andrew |
Taille de l’image : | 5445 px × 3565 px |
Model Release : | Le droit n'est pas encore disponible. Merci de nous contacter avant utilisation. |
Property Release : | Non requis |
Restrictions : | - |