Includes 1. What is a Retinoscope? 2. Short History of Retinoscope 3. Parts of a Retinoscope 4. Detailed Optics of a Retinoscope 5. Practical Points of Retinoscopy

1. Retinoscope
Dr. Muhammad Zeeshan
Postgraduate Resident
Department of Ophthalmology
DHQ Teaching Hospital, Gujranwala

2. What is a Retinoscope?
 An accurate objective measurement of
the refractive state of an eye can be
made using an instrument called the
retinoscope.
 The technique is called retinoscopy,
pupilloscopy, shadowscopy,
skiascopy, umbrascopy or
scotoscopy.

3. A Short History of Retinoscopy
 F. Cuigent (the father of retinoscopy) – first
described a retinoscope in 1873
 Jack C. Copeland introduced Streak
Retinoscope in 1927

4. Parts of a Retinoscope

5. Principles of Retinoscope
1. Illumination Stage: Light is directed on
patient’s retina
2. Reflex Stage: Image of retina is formed at
patient’s far point
3. Projection Stage: Image is located by
moving illumination across fundus and noting
behavior of reflex (with or against movement)

6. 1. Illumination Stage

7. Illumination Stage

8. Illumination Stage

9. Illumination Stage
Plane-Mirror Effect:

10. Illumination Stage
Plane-Mirror Effect Benefits:
1. More illumination with bright light
2. Easy retinoscopy especially in
• Small pupils
• Media opacities

11. 2. Reflex Stage
Ray 1:
A ray from point A of the retina R on the principal axis of the
eye, which leaves the eye along the principal axis

12. Reflex Stage
Ray 2:
A ray from a retinal point B, off the principal axis, which travels
parallel to the principal axis as far as the principal plane, P, of the
eye, where it is refracted to pass onward through the anterior
principal focus, Fa, of the eye.

13. Reflex Stage
Ray 3:
A ray from retinal point B which passes undeviated through
the nodal point, N

14. Reflex Stage

15. 3. Projection Stage
A ray from B1 passes through observer's nodal point, No, to
the observer's retina, Ro. This ray locates Bo, the image of
B1 on the observer's retina.
The observer does not see the actual image A1B1, but rays
from A1B1 are seen as an illuminated area or reflex in the
patient's pupil.

16. Projection Stage
In hypermetropia the reflex seen in the patient's pupil
moves in the same direction as the illuminating light –
a 'with' movement.
When the patient's myopia is less than the dioptric
value of the observer's working distance a 'with’
movement is still obtained.

17. Projection Stage
When the patient's myopia exceeds -1.5 D, the image
A1B1 falls between the patient and the observer. The
reflex appears to move in the opposite direction to
the illuminating light; 'against' movement.

18. Projection Stage
Point of Reversal / Neutral Point:
When the patient's far-point coincides with the
observer's nodal point. No image of B1 can be formed
on the observer's retina and no movement can be
observed in the patient's pupil.

19. Projection Stage
In practice, lenses are placed in front of the
patient's eye until the point of reversal is seen by
the observer.
A correction is made for the working distance (add
–1.5 D for 2/3 m, add –1.0 D for 1 m) and the
corrected value of the lenses equals the patient's
refractive error.