Page 126 - The Indian Optician Digital Edition May-June 2023

CONTRAST SENSITIVITY

AND STEREOACUITY

IN PRESBYOPIC SUBJECTS WITH THE IPAD

resbyopia is a common age-related visual disorder
that causes a progressive inability to focus on
Pnearby objects. The exact cause of presbyopia
is not fully understood, but recent research suggests
that an increase in lens rigidity is the primary factor.
The ciliary muscles may weaken or the lens may lose
OPTOM PARTH N. VORA elasticity, preventing the focal point from changing.
PURSUING M. OPTOMETRY Accommodation, the ability of the eye to adjust focus,
NAGAR SCHOOL OF OPTOMETRY, also decreases as the lens loses elasticity. Around the
AHMEDABAD
fifth decade of life, accommodative amplitude declines
to the point where the near point of the eye is farther
away than the reading distance, and accommodation
decreases to essentially 0D by the age of 60, which is
when patients are considered absolute presbyopes.
The Merriam-Webster dictionary defines presbyopia as
"a visual condition that becomes apparent, especially
in middle age, in which the loss of elasticity of the lens
of the eye causes defective accommodation and an
inability to focus sharply for near vision."
Spectacles are typically considered the most
convenient option for addressing the symptoms of
presbyopia. Single near-vision spectacles have a single
focal point that is suitable for a specific distance,
requiring individuals to remove them or use a separate
DR. USMAN MEMON pair of spectacles for distance viewing. Bifocal, trifocal,
PH.D, M. OPTOM, B.SC., FIACLE, PGDIM or progressive addition spectacle lenses (PALs) have
different optical power zones for viewing objects at
various distances. It is also possible to combine multiple
prescriptions into one lens for everyday use.
There are several contact lens options available for
correcting presbyopia, including single-vision distance
contact lens correction with reading spectacles,

122 | THE INDIAN OPTICIAN | MAY-JUNE 2023 OPTOMETRY