Prerequisite: Born with it
You can see normally when you try to see things farther away, but you have difficulty seeing things close by. For targets less than 20 feet away, you have disadvantage on Perception checks involving sight, and disadvantage on melee attack rolls. You also have trouble reading anything closer than 20 feet away.
FLAW. This is a flaw feat. Some flaws can be overcome in time, with role played work towards that end. Others might be overcome by a high-level Cleric, but the cost might involve a side quest or a great amount of money.
However, you have advantage on ranged attacks and actions farther than 20ft.