2. Cross cylinder
• Waxaa sameeyay nin la oran jirey jacksons cross cylinder
wuxuuna ka kooban yahay labo cylinder (2 cylinders ) oo isku
awood ah (same power ) laakiin kala calaamad duwan (with
opposite sign).
3. Waxa loo isticmaalo ( uses )
• In lagu ogado inuu bukaanku ubaahan yahay cylinder iyo in
kale ( to know if the patient need cylinder or not )
• Haduu bukaanku cylinder ubaahan yahay , in lagu ogaado AXIS
kiisa saxda ah ( to refine the axis of the cylindrical lens )
• Sidoo kalena lagu ogaado POWER ka saxda ( also to refine the
power of the cylindrical lens )
•
4. Sida lagu ogaado qofka inuu cylinder
ubaahan yahay iyo in kale ( to know if
the patient needs cylinder or not )
• Hordhig cross cylinderka , spherical lenseska patient ka
hortiisa , axiska cross cylinderkana ka dhig 90 degrees sida
sawirka ka muuqata.
5. • kadibna ugadi cross cylinderka dhinaca +0.25 , iyo -0.25 , oo
bukaanki weydii ladaba dhinac inuu wax isbedel eh jiro ( flip
the cross cylinder into +0.25 and – 0.25 sides , and ask the p
• atient if there is difference )
• Haduusan wax isbedel ah jirin , axiska 90 degreeska ka badal
oo sidoo kale ku fiiri 180 degrees sida sawirka ka muuqata
• sidoo kale 45 degrees iyo 135 degrees
6. • 3)haduu intaas AXIS ee aad ku check gareysay , patientka wax
farqi eh dareemin , markaa uma baahna cylindrical lens ( if the
patient feels no difference in both flips , that means he don’t
need cylindrical lens ).
• 4)Hadii labada dhinac ee +0.25 ama -0.25 midkood uu
bukaanku u arko iney ka wanaagsan tahay ta kale , markaas
wuxuu ubaahan yahay cylindrical lenses , oo waa astigmatic
patient ( if the patient appreciates one of the flip positions ,
that means he need cylindrical lens )
• Cylindrical lens ka aad siineeysidna ha lahaado axiska uu ku
arkey inuu farqi jiro ( give the cylindrical lens in which the
patient felt better )
7. Sidalooogaado AXISka uuubaahanyahay
bukaanka(howto refinetheaxisofthepatient)
• Waxaa ugu horeyn la ogaadaa AXIS ka uu bukaanka ubaahan
yahay , sababtoo ah waad ogaan kartaa AXIS ka bukaanka
adigoon ogeyn powerkiisa saxda ah.
• Hordhig cross cylinderka , bukaanka cylinderka uxiran hortiisa ,
kadibna handle ka ama meesha laga qabto cross cylinderka
waxaad ku aadisaa axiska cylinderka bukaanka sida sawirka ka
muuqato
• ( align the handle of the cross cylinder with the axis of the
cylindrical lens of the patient as shown in the pic )
8.
9. • kadib cross cylinderka ugadi marna dhinaca +0.25 , marna -
0.25 ( flip the cross cylinder in positive and negative sides ) ,
kadibna weydii haduu wax farqi ah udhaxeeyo
• haduu bukaanku yiraahdo wax farqi ah uma dhaxeeyo ,
waxaad heystaa AXIS ki saxda ahaa .
• hadii laba dhinac mid uu wanaagsanaado , ( tusaale ahan
haduu bukaanku yahay +2.00 cylinder , markaas waxaan axiska
5 degrees uwareejineynaa dhinaca axiska cylinderka naga jiro
(if the patient wears positive cylinder , we turn the axis 5
degrees towards it ) .
10.
11. • haduu bukaanku cylinderka uu wato ay tahay -2.00 , axiska
waxaan 5 degrees u wareejineynaa caksiga axiska cylinder ka
sida sawirka ka muuqato ( if the patient wears negative
cylinder , we turn the axis 5 degrees away from it ).
•
12. Sidalooogaado POWERkauu ubaahanyahay
patientiga(to refinepower)
• si aad powerka u hesho waxaad AXIS ka cross cylinderka ku
aadinee , AXIS ka patient cylinder sida sawirka ka muuqata ( a
lign the axis of the cross cylinder with the axis of the patients
cylinder )
13. • 2)kadibna gadi cross cylinderka , marna dhinaca +0.25 , marna
dhinaca -0.25 , oo weydii bukaanka dhinaca uwanaagsan .
• 3) hadii labada dhinac isugu mid yihiin , waa powerka saxda ah
ee uu patientka ubaahan yahay .
• 4)hadii patientku si fiican wax uuga arko dhinaca (+) , yaree
cylindrical powerka ( if the patient appreciates the plus side ,
then decrease the cylindrical power) .
• 4) haduu si fiican wax uugu arko dhinaca (-) , u kordhi
cylindrical powerka (if the patient appreciates the minus side
, then increase the cylindrical power).
•