Which diopter range is used to examine the vitreous with a direct ophthalmoscope?

Which diopter range is used to examine the vitreous with a direct ophthalmoscope?

• A. +2 to +5
• B. +5-6
• C. -2 to -5
• D. +6 to +7

Answer: (A)

When using a direct ophthalmoscope, the diopter setting determines how the eye’s internal structures come into focus through the instrument. For looking at the vitreous, you want enough focus to bring the posterior segment into view without overmagnifying or narrowing the field excessively. A modest positive correction in the +2 to +5 diopter range provides a suitable focal plane for the vitreous, allowing you to see vitreous strands, floaters, or hemorrhage clearly while keeping illumination and field of view practical. Higher positive settings (+6 to +7) increase magnification and shrink the viewing field, making the vitreous harder to assess; negative diopters shift focus anteriorly and do not reveal the posterior structures well. Therefore, +2 to +5 is the best range for examining the vitreous with a direct ophthalmoscope.

When using a direct ophthalmoscope, the diopter setting determines how the eye’s internal structures come into focus through the instrument. For looking at the vitreous, you want enough focus to bring the posterior segment into view without overmagnifying or narrowing the field excessively. A modest positive correction in the +2 to +5 diopter range provides a suitable focal plane for the vitreous, allowing you to see vitreous strands, floaters, or hemorrhage clearly while keeping illumination and field of view practical. Higher positive settings (+6 to +7) increase magnification and shrink the viewing field, making the vitreous harder to assess; negative diopters shift focus anteriorly and do not reveal the posterior structures well. Therefore, +2 to +5 is the best range for examining the vitreous with a direct ophthalmoscope.