The visual sensitivity of a human being is from about NUMBER@1 ångströms -LRB- violet -RRB- to NUMBER@2 ångströms -LRB- dark red -RRB- so the use of the ångström as a unit provided a fair amount of discrimination without resort to fractional units .

The visual sensitivity of a human being is from about NUMBER@1 Ångstroms -LRB- violet -RRB- to NUMBER@2 Ångstroms -LRB- deep red -RRB- so the use of the ångström as a unit provided a fair amount of discrimination without resort to fractional units .
