A development of keratoscopy, corneal topography extends the measurement range from the four points a few millimeters apart that is offered by keratometry to a grid of thousands of points covering the entire cornea. The procedure is carried out in seconds and is completely painless. 1 Operation.
Other melons - Cantaloupe, Cranshaw, Honeydew, etc. - 30 min. Oranges, grapefruit, grapes - 30 min. Apples, pears, peaches, cherries, etc. - digest in 40 min. Vegetables: Raw tossed salad vegetables - tomato, lettuces, cucumber, celery, red or green pepper, other succulent vegetables - 30 to 40 min. digestion.
Quick Answer. Lettuce is typically digested within 24 to 72 hours. Only bulkier foods, like nuts and celery, digest at somewhat slower rates in the stomach, but pass through the digestive system more easily after being digested by the stomach.