$25.$Suppose that the lens in a particular eye has afocal length that can vary between $1\mathrm{.}85$ cm and $2\mathrm{.}00$ cm$,$but the distance from the lens to the retinais only $1\mathrm{.}90$ cm$.($a$)$ Is this eye nearsighted or farsighted?$($b$)$ What range of distances can theExplain.without corrective lenses?eye see clearly