What are the advantages and disadvantages of soft and rigid gas permeable contact lens?

What are the advantages of soft contact lens?

• Good initial comfort
• Ease of adaptation.
• Natural facial expression and head posture.
• Long wearing times.
• Low incidence of oedema.
• Rare occurrence of overwear syndrome.
• Absence of spectacle blur.
• Maintenance of corneal sensitivity.
• Good for intermittent wear.
• Low incidence of photophobia and lacrimation.
• Low incidence of flare, even with large pupils.
• Low risk of loss.
• Good for sports.

What are the disadvantages of soft contact lens?

• Astigmatism is not corrected with spherical lenses.
• Variable vision.
• Near vision problems.
• Lens dehydration.
• Liable to damage.
• Deposits and ageing with conventional lenses.
• Disinfection and hygiene essential.
• Solutions allergies.
• Lens cleaning is more difficult.
• Lens contamination.
• Limited life span.
• No modifications possible.
• Difficult to check.
• Conventional trial lenses are no longer available.
• Expensive to maintain or replace regularly.

What are the advantages of hard gas permeable contact lens?

• Excellent visual acuity
• Correct corneal astigmatism.
• Variety of complex designs available.
• Ease of maintenance.
• Few solutions allergies.
• Minimal deposits with proper cleaning.
• High oxygen permeabilities.
• Do not cover the entire cornea.
• Tear pump on blinking.
• Good long-term ocular response.
• Easy to check.
• Modifications possible.
• Lenses available in a range of tints.

What are the disadvantages of hard gas permeable contact lens?

• Initial discomfort.
• Precise fitting required.
• Stringent regulations concerning the use and disinfection of diagnostic lenses.
• Foreign bodies.
• Risk of loss.
• Lens adhesion.
• Breakage and scratching.
• Greasing with some people.
• Instability of some materials.