Absence of an accommodative lag may indicate latent hyperopia. It can also occur as a result of a spasm of accommodation.
In some animals this adjustment occurs either as a result of an anteroposterior movement of the crystalline lens, or of an alteration in the curvature of the cornea.
See aniso-accommodation; ciliary muscle; accommodative reflex; Fincham's theory; Helmholtz's of accommodation theory.amplitude of accommodation The maximum amount of accommodation A that the eye can exert.
In middle age PRESBYOPIA becomes apparent in all but the near-sighted. It is generally involuntary and made to see objects clearly at any distance.
In man (and primates), this adjustment is brought about by a change in the shape of the crystalline lens.
Spectacles induce less accommodation in myopes and more accommodation in hyperopes than that exerted by an emmetrope fixating at a given distance.