It is not a refractive error but a physiological insufficiency of accommodation. It leads to progressive fall in near vision. Decrease in the accommodative power of crystalline lens due to increasing age related conditions , leads to presbyopia. 1. decrease in the elasticity and plasticity of crystalline lens. 2. decease in the power of ciliary muscles. Some conditions to generate premature presbyopia - 1 uncorrected hypermetropia 2. premature sclerosis of crystalline lens 3. weakness of ciliary muscles. 4. chronic simple glaucoma SOME SYMPTOMS - fever, blurring, asthenopic symptoms, fatigue, illness, diplopia TREATMENT - bifocal lens, trifocal lens and progressive addition lens convex lens should be prescribed to correct presbyopia.

1. PRESBYOPIA

2. CONTENTS
 DEFINITION
 PATHOPHYSIOLOGYOFPRESBYOPIA
 CAUSESOF PREMATUREPRESBYOPIA
 SYMPTOMS
 TREATMENT
 MODESOF PRESCRIBINGPRESBYOPICADDITION

3. DEFINITION
 It is not error of refraction, but a condition of
physiological insufficiency of accommodation leading
to a progressive fall in near vision.
 This condition of failing near vision due to age related
decrease in the amplitude of accommodation or increase
in the near distance is called PRESBYOPIA.

4. PATHO-
PHYSIOLOGY
OF
PRESBYOPIA
Decrease in the accommodative power of crystalline
lens with increasing age, leading to presbyopia, occurs
due to –
 Decrease in the elasticity and plasticity of the crystalline lens
 Age related decrease in the power of ciliary muscles.

5. CAUSESOF
PREMATURE
PRESBYOPIA
 Uncorrected hypermetropia
 Premature sclerosis of the crystalline lens
 General debility causing presenile weakness of ciliary
muscles.
 Chronic simple glaucoma

6. SYMPTOMS
 Difficulty in near vision
 Asthenopic symptoms
 Diplopia
 Fatigue
 Illness
 Fever

7. TREATMENT
Testing of presbyopia should be done monocularly as
well as binocularly.
OPTICALTREATMENT-
 It should be done by supplementing accommodation
with convex lens of appropriate power required for a
clear and comfortable near vision.
 The difference b/w the distance correction and the
strength needed for near vision is called the ADDITION.

8. A ROUGH ESTIMATION –
 40 years : +1.00D.to +1.25D
 45years : +1.25 to 1.50 D
 50 years : +1.50 to 2.00 D.
 55 years : +2.00 to 2.50 D
 60 years : +2.50 to 3.00 D

9. MODEOF
PRESCRIBING
PRESBYOPIC
ADDITION
Correction of presbyopia can be prescribed following
ways :
 Single vision reading glasses
 Bifocal glasses
 Trifocal glasses
 Multifocal glasses
 Varifocal glasses