Long sight (Hyperopia)
Also called hyperopia, this means that close-up objects (and often distant objects) may be out of focus.
This occurs because the eyeball is too short for light to focus on the retina (see diagram upper right).
Unlike in myopia, in hyperopia the eye can ‘accommodate’ (adjust its own focusing strength) to temporarily compensate for part or all of the refractive error, but this requires muscular effort that can lead to eyestrain, headaches and other symptoms of visual stress.
A spectacle or contact lens of the correct power changes the path of the incoming light so that it focuses perfectly on the retina without any extra assistance from the eye’s accommodative mechanism, as it would in a normal eye (see diagram lower right).
Glasses may be needed for reading, VDU work, driving and watching TV. Many hyperopes prefer to wear their glasses all the time.
Everyone’s vision changes over time and you may experience one or more of the above conditions. That is why it is important to have regular eye examinations.
All images on this page have been supplied courtesy of Hoya Lens UK.