Near Vision Flashcards
What is accommodation?
‘Accommodation’ refers to the process of the focal point of the eye shifting from a distant target to a near target.
At what age does presbyopia manifest in hypermetropes?
from age 35 years
Why is it good to assess near vision with illumination?
Near vision is also improved by pupillary constriction, which increases the depth of focus. Adequate macular function is also vital for satisfactory near vision.
What is the estimated near add for a patient aged 40-50 years
+1.00 to +1.50
What is the estimated near add for a patient aged 50-60 years
+1.50 to +2.50
What is the estimated near add for a patient aged >60 years
+2.50 to +3.00
What is the estimated near add for a pseudophakic patient
+2.50 to +3.00
What is the distance for reading on average (cm)
33cm
How to assess near vision?
Occlude the left eye and ask them to read the smallest print they can on the N- Series reading chart held at their working distance. Now add the appropriate near plus lens and record the corrected near acuity (aiming for N5 or N6 in the absence of ocular disease).
Ask them to look at a letter, then ask:
Is the letter clearer ‘with [placing a +0.25 ds in front of their eye] or without the lens (remove the +0.25 ds], or about the same?
If the patient reports that the reading is better with +0.25 lens?
give the +0.25 ds and repeat until acuity is optimal.
When might a patient have a high near add in one eye and a small near add in the other eye?
The patient’s near add is typically the same for both eyes, but this should still be checked as pre-presbyopes that have had unilateral cataract surgery will require a high near add in their pseudophakic eye and perhaps only a small near add in their phakic eye.
