Myopia is said to be caused by an elongation of the eyeball. This means that the oblong (as opposed to normal spherical) shape of the myopic eye causes the cornea and lens to focus at a point in front of the retina.
1 Bonds pay interest every six months until they mature. When a bond matures, the owner is paid the face value of the bond. 2  Bonds can be held until maturity or sold before maturity.  More about Treasury bonds rates and terms in the Research Center.
What HH bonds earn. Series HH bonds pay a fixed rate of interest from the date you purchased the bonds. The present rate is 1.5 percent and has been in effect since January 1, 2003. This rate is locked in for twenty years after purchase, after which Series HH bonds will stop paying interest.