Rx Classification

[amitverma1]

consider the following and determine the type of refractive error(s). Classify the astigmatism further if any:

OD: +2.00 -3.00 180 Add: +1.25

If I were to classify the above rx in simple terms, it would be:

Hyperope, Mixed Astigmat, Presbyope.



Now if I have PLANO -3.00 180 Add: +1.25

should it be Emmetrope, Simple Myopic, Presbyope ??

I want to know if I would be correct to use Emmetrope in this case. Since Emmetrope means no correction needed but this person has astigmatism correction so this person is not Emmetrope. At the same time I am classifying the Sphere and cyl separately.

[Chris Ryser]

Transpose you Rx and you get the following :

Now you have +3.00 -3.00 90 Add: +1.25

[uncut]

Welcome to the forums, amitverma1!

I believe you are correct in classifying the second Rx as Emmetrope, although Emmetropia is the measurement of a normal eye, and Ametropia is the measurement of the abnormal eye? The astigmatism is myopic, but within the classification definitions of regular, irregular, corneal,residual, or lenticular, I would choose "regular".
The information given limits the description.
The person is certainly a Presbyope, classified, I think as a Early Presbyope, perhaps?

Good luck(I'm assuming) with your studies!

[fjpod]

I believe your second case would be classified as a simple myopic astigmat. You're only a true emmetrope if all meridians are free of refractive error.

Also, I believe that transposition would be -3.00 + 3.00 x 90...still a simple myopic emmetrope.

[amitverma1]

Thanks to all. Uncut I am acutally an optician. LOL. You can assume I am a student since I am still learning. Actually I am developing a website for students. I want students to look at Rx, and quickly classify and visualize it. I came across this type of question in "optics formulae tutorial 2" in which you classify the type of astigmatism i.e. Simple Myopic, Compound Hyperopic and so on. I am taking it a little further by defining the full Rx.

The reason I picked Plano example, because its not basically a myope(-) or a (Hyperope)(+), its neutral. My confusion was between Hyperope (plano is still a positive number) or Emmetrope. The way Chris described is obvious transposition that I have to do to find out the type of astigmatism, but doesn't change the original question. I guess I am trying to break my question into 3 parts,
1. Myope, Hyperope or none(emmetrope)
2. Astigmatism type(if any),
3. Presbyope(if any add power)

So I am going to go with Emmetrope as you and fjpod described since we look at power only when you consider for part 1 above in my case