Vision measurement: eye doctors have you look at lines of print of various sizes and introduce lenses of various powers to improve the clarity of the letters. If you need lenses of more than a minimum power to see clearly, then 'u' need glasses.
Answered 11/10/2014
4k views
A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more.
Ask your question