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.
Along with drops, ointments are the most common way to treat many eye problems. Because they go right into your eye, they can start to work much faster than a medicine you take by mouth. Eye ointments are drugs in a greasy, semisolid form. Your body warmth makes them melt. Once you apply ointment to your eye, it breaks into tiny drops. These hang out between your eyeball and eyelid for a while. Thatâs what gives the medicine time to work. Eye ointments are a safe treatment. Most people handle them well. But they might sting or make your sight blurry. Because of that, your doctor may suggest you use them right before bed. Why Do You Need It? You could be given eye ointment for a number of reasons.