OCTOBER 2018 Sub. Code: 1604
M. OPTOM DEGREE EXAMS
FIRST YEAR
PAPER IV CONTACT LENS I
Q.P. Code: 281604
Time: Three hours Maximum: 100 Marks
I. Elaborate on: x 20 40)
1. Explain characteristics of flat and steep rgp lens with example and their
modification with rule of thumb with simple myopic, simple myopic astigmatism
and hyperopic prescriptions and assumed K reading, HVID of 11.5 mm.
2. What is the recommended lens for a patient who is 23 years female, who performs
works for 12 hours and having power of -5.00ds/2.00X90 in both eyes? Patient
gives a history of trying different soft and toric lenses which led to allergy and
papillae. Explain the fitting procedure of the chosen lens type and give final
prescription.
II. Write notes on: (10 x 6 60)
1. State the differences between rigid material and soft hydrogel material from the
early materials to those available now a days.
2. Explain the relationship between sag, base curve and diameter and their rule of
thumb with examples.
3. Explain methods of contact lens fit assessment in soft, spherical rgp and toric soft
lens.
4. List special instructions for dispensing a RGP lens for a patient. List the points
required in teaching.
5. Explain corneal anatomy and in relation to contact lens.
6. Explain functions of tear film and their properties. Explain different layers of tear
film and their secretion.
7. List the investigations required before contact lens fitting.
8. Explain characteristics of flat and steep rgp lens with example and their
modification with rule of thumb.
9. What is wettability of lens what are the advantage of low and high water content
lens? Give examples of cases in which you will prescribe them.
10. Explain slit lamp examination methods for contact lens practice.