Near visual acuity is a measurement of how well you can see close objects. Usually measured at about 16 inches, it is a good way to measure your ability to cope with tasks such as reading or sewing. In most cases, near visual acuity is measured with both eyes open.
He was a Dogue de Bordeaux (French Mastiff), and Turner and Hooch (1988) was his first and only movie. He played the house-wrecking police dog who drank beer.
When Turner is on stakeout with Hooch, Turner is wearing glasses when he tastes the dog biscuit. When he feeds the biscuit to Hooch you can see his glasses on the dash. He then puts them on again in the next shot.