Dominant genes are genes that express themselves over recessive genes. This are expressed on such individual and are visible phenotypically. While recessive genes are genes whose effect are masked and not expressed. They may be present in the genome of an individual but are not usually expressed.
For an individual with a dominant tall eye ball(T)over short eye ball(t), Tall eye ball will always be expressed as TT having similar allele or Tt with a different allele but in a dominant form.
