You are right. Stay with us and share with your friends. Don't forget to download our app "Optometry Notes & MCQs". It's available in Google Play Store. Thank You, Samir Sutradhar.
Thank u , i have 2 questions one :Explain mathematically why the human eye can distinguish the largest letter of Snellen chart from a distance of 60m specifically? 2: how to prove that the mar =1 min arc mathematically ?
@@optometry-with-samir Great video! I just subscribed to your channel! How would the use formula for a near snellen visual acuity chart? What would be the new D values, because the distance and near snellen charts are written in the same format? but the card is help at 40cm
There is no specific formula as far as I know. On an average -0.50DS is equivalent to each line in Snellen Chart. Hyperopic patient can read 6/6 line even with +3 to +4D hypermetropia depending upon amplitude of accommodation.
@@atullendave6195 The letters are fit into a square that is five times of constituent line. Easily, You can identify the thickness using formula: Height or Width of Letter/ 5
Thanks for formula bro ❤
You are right.
Stay with us and share with your friends.
Don't forget to download our app "Optometry Notes & MCQs". It's available in Google Play Store.
Thank You,
Samir Sutradhar.
Tq so much. But you know now a days the snellen chart use 6/5 letters at the end . But all the medical examination says that the last line is 6/6
Even few chart has 6/4 also... According to ICD 10: Low Vision Classification, 6/12 to 6/6 is considered normal visual acuity.
Thank u , i have 2 questions one :Explain mathematically why the human eye can distinguish the largest letter of Snellen chart from a distance of 60m specifically? 2: how to prove that the mar =1 min arc mathematically ?
Thanks for the great video! How does this change for creating the optotype size when using a 10 feet chart? eg 10/10, 10/40, 10/60 etc
Convert the Denominator in meter then use the formula..
Nice explanation, this is for 6/60 , for (6 meter chart) please tell me how to do for 3 meter chart for 3/60, 3/36..and all.
Thank you! Can this also be used for a near visual acuity snellen chart?
Yeah,
You can use this for Snellen Near Visual Acuity Chart.
@@optometry-with-samir Great video! I just subscribed to your channel! How would the use formula for a near snellen visual acuity chart? What would be the new D values, because the distance and near snellen charts are written in the same format? but the card is help at 40cm
@@andya1408
Convert 40 cm in meter in try this formula
@@optometry-with-samir But how would you apply the D values to all of the different near VA values? eg for N8, N6, N10, N12 etc?
@@andya1408
This formula is for Snellen Near Visual Acuity Chart not for Roman font letter size...
Where did the 18.288 cooke from
@@chizzy-y7s
For the Formula we need meter but in the example it was in Feet.
60 feet equal to 18.288 meter
thank you sir for the vid.
sir may i ask you about how to correlation between snellen fraction and spherical /cyl correction?
how to calculate it?
There is no specific formula as far as I know. On an average -0.50DS is equivalent to each line in Snellen Chart.
Hyperopic patient can read 6/6 line even with +3 to +4D hypermetropia depending upon amplitude of accommodation.
But sir how to calculate the thickness of letters
It also matters in vision
Plz give formula for thickness also
@@atullendave6195
The letters are fit into a square that is five times of constituent line. Easily, You can identify the thickness using formula: Height or Width of Letter/ 5
Request to reply what is starting salary after diploma optometry without BSc optometry in Patna AIIMS and PMCH
We don't have any idea. We Will come back to you if we get any info regarding this.