Hyperopia
Long sightedness does not affect your distance vision, but it does affect your ability to focus on near objects. Both forms of long sightedness are perfectly normal and easily treatable.
[embedyt] http://www.youtube.com/watch?v=ph4RNUoKusM[/embedyt]
Myopia
Short sightedness does not affect your close up vision, but it does affect your ability to see objects further away. It may be more difficult to recognise faces at a distance and driving may become more difficult too. In children, short sightedness can be recognised when they have difficulty seeing the blackboard in their classroom, or watching television from a distance.
Astigmatism
Astigmatism is a common eye condition, that is usually minor, and can cause blurred or distorted vision.
It occurs when the cornea or lens is not a perfectly curved shape. Most people who have astigmatism wear glasses. If left untreated astigmatism can also cause headaches and eye fatigue.
Astigmatism is usually diagnosed after a routine eye test, which often involves testing your ability to focus your eyes. Treatment where your vision is significantly affected by astigmatism, would be glasses or contact lenses.
[embedyt] http://www.youtube.com/watch?v=pST6h0aelbY[/embedyt]
Presbyopia
Presbyopia is a normal age related eye condition that makes it more difficult to see things very close up.
Usually, around the age of 40 the lens begins to become more rigid and cannot change shape as easily and as a result it becomes more difficult to read at close range.
[embedyt] http://www.youtube.com/watch?v=sY0zMAax_Sw[/embedyt]