Gravel /ËÉ¡rÃ¦vÉl/ is a loose aggregation of rock fragments. Gravel is classified by particle size range and includes size classes from granule- to boulder-sized fragments. In the Udden-Wentworth scale gravel is categorized into granular gravel (2 to 4 mm or 0.079 to 0.157 in) and pebble gravel (4 to 64 mm or 0.2 to 2.5 in).
OD - This is shorthand for oculus dextraous which means Right Eye. OS - This is shorthand for oculus sinister which really means Left Eye. OU - This is shorthand for oculus uterque which really means Both Eyes. If you see this, you'll want to enter the prescription the same on both eyes. Sphere or Power - SPH or PWR - This is the main strength of your eyeglass prescription, and is written in 0.25 increments. If the field has 'SPH', 'PL', 'PLANO', or '00', this means your there is a 0.00 power as should be entered as so.
Oral appliances (OA) that treat snoring, UARS, and OSA are devices worn in the mouth similar to sports mouth guards or orthodontic retainers. They are made of plastic and fit partially or completely within the mouth. Currently there are over 40 different types of oral appliances available. OAâs may be used alone or in combination with other means of treating sleep apnea, such as weight management, surgery and CPAP. There is no one particular appliance that will work for every patient.