scotoma
the fovea centralis is the point of clearest vision
Assuming that the man who has normal vision is homozygous for normal vision, the couple's daughter will either be homozygous for normal vision or heterozygous (normal vision but carrier for color blindness) for normal vision. In light of this, the couple's daughter will not be color blind.
which of the following indicates normal vision at 20 feet
It is not impact our vision.
America? :)
Emmetropia
Emmetropia is basically normal vision, or a state of vision in which far objects are in sharp focus, with the eye lens in a normal state.
The fovea lacks rod cells, which are responsible for low-light vision. Instead, the fovea is densely packed with cone cells, which are responsible for color vision and detailed vision in bright light conditions.
30 50 is considered mild vision loss, or near-normal vision.
Peripheral vision is the type of vision that is useful in sensing motion and objects outside of normal vision range. It allows us to detect movement and objects in our surroundings without directly looking at them.
Usually a Snellen's Chart is used to assess vision.
It means seeing at 20 feet what a person with normal vision sees at 20 feet. A person who has 20/40 vision can see at 20 feet what the person with normal vision sees at 40 feet, etc. Some people have better than 20/20 vision.